Tuesday, December 4, 2012

More work on the 147.39 repeater...

More repairs were made to the 147.39 repeater yesterday (Sat, 12/1). I met with Matt, Alex, Sam, Roger, and even Jose (for a few minutes) at the site, and work started. Over the next four hours, several things were accomplished.

We retuned all of the receive & transmit cavities, and found them all to be out of adjustment...some by quite a bit. They were last adjusted back in 2002. We changed the configuration of the cavities to improve isolation, and have an additional pass cavity on the receive and transmit ports. De-sense is gone, and all is well with that aspect of the repeater, now.

All 4 cooling fans were replaced. They run non-stop, and have turned many revolutions since the installation of this repeater at the Clayton site in 2002. All of the heat sinks are cleaned, and the repeater is running nice and cool.

A temporary repair had been made a while back with a jumper lead, and that was removed and hard wired to correct a control logic problem. There is one more similar issue, but I forgot my glasses and couldn't see the terminal that needed to be soldered :-)

Weak signal tests were made, and it is responding to signals that are right down in the noise, so we're pretty happy with that. A few programming changes were made, and that wrapped up the work for the day.

The "to-do" list is getting short now with only a few items left like: replacing a defective PL encoder board on the transmitter, repairing a control logic issue for the 2nd voice announcer module, and replacing a backup battery on the voice IDers.

Next, the work on the Clayton site begins...

147.39+ WB4IUY Repeater work...

147.39 repeater work underway... A good bit of work is being done to the 147.39 repeater. Chris, Sam, Alex and myself went out to the site last Saturday (11/24/12) and found the dirtiest repeater in operation on this planet...really :-) To qualify this, the repeater has been running hands off for at least 2 years, maybe 3, so I had no reason to go to the site to check on things. I had no idea the site/repeat er/tower/antenna had deteriorated to such a sad state...

The property owner now stores hay for 18 horses in the rear of the barn in the area where the repeater lives. The floor was at least 6" deep in hey stems and very finely ground chaf from hey. The upper & lower repeater cabinets were completely clogged with hay, chaf, and cobwebs/spiderwebs. The fine dust, which had some of us coughing and sneezing, was at least an inch deep inside of the repeater on some of the electronics to such a point that much of the wiring was completely hidden and all 5 cooling fans were seized up. Heat sinks on driver, power amp, voltage regulators, etc were clogged with the same stuff. I honestly don't know why the repeater had not blown up and/or caught fire. Additionally, the lower cabinet where the duplexers and other items live were in the same condition. It also seems that a dog had found an opening into the rear of the enclosure and has been using the lower section of the bottom cabinet as a toilet and was literally covered in copious amounts of doggie poo.

We pulled out all of the repeater releated equipment, loaded it up, and hauled it off for cleaning and re-installation. It has now been cleaned pretty well, reconnected at a clean site, and is receiving some much needed repairs while keeping it on the air as best as possible. It is suffering from some desense issues at the moment, but more work is planned for Saturday. It should be up and running well in time for the Tuesday night net. We'll also be making some controller and other changes that should improve coverage and functionality.

Tower: We discovered several serious antenna related issues. The tree that had grown up into the tower has been trimmed and the most pressing parts cut away from the tower. There are still a couple of limbs to remove, and I'll get to that shortly. The more significant issue is where someone has run into the southwest elevated guy point and sheared off the backup restraint that ties it to the primary anchors. This allowed the elevated guy point to pull towards the tower, loosen the 3 lower SW guy wires, and allow the bottom 1/3 of the tower to slowly curve towards the northeast. I've got to repair that right away, before an ice storm and tower loading causes the tower to fall. There are also a few ice splits in the lower section that have to be repaired.

Antenna: Examination of the top mounted 4 bay dipole array that has served 147.39 for about 20 years revealed more problems... One of the top folded dipoles has loosened and turned towards the mast about 90 degrees. Another of the folded dipole loops is completely missing and no where to be found on the property. The link antenna has blown around and the multiband vertical is twisted in a pretty bad band. Again, I'm amazed that the system was still working as well as it was.

Saturday, December 1, 2012

WB4IUY Repeater Bulletins, back to 1992!

This is dull reading, but I wanted to get these repeater bulletins on the blog before they were lost forever. These are posts I made online about various repeater problems and repairs, from 1992 to 2012. If you're considering putting a repeater on the air, look over these and think about it long and hard :-) 

I've spent hundreds of hours over the years building / installing / maintaining these things. They were a labor of love, for sure. Repeaters are radio systems that are on the air, 24/7/365. Subjected to everything nature and people can throw at them. They have a rough life and must be built TOUGH. 

On top of typical electronics failures, I've spent hnndreds of additional hours dealing with extreme temperatures, huge power surges, fires, lightning strikes, people hacking the controllers in the middle of the night to try and screw things up, theft, water damage, fire ants that tooke over one of the sites, rust on outdoor cabinets, water in feedline, mice at repeater sites, site owners who covered up the ventilation systems and causing over-heathing, well-intentioned helpers who cleared memory and ALL programming, intentional jamming, unintentional interference from local and distant signal sources, noise from tower rectification, and more...

Current Repeater Bulletins

12/1/2012 - Several repairs and adjustments were made to the WB4IUY 147.39 repeater and tests performed from the new Apex location. Learn more about it HERE.

11/24/2012 - The WB4IUY 147.39 repeater was removed from Clayton for major repair and relocation. Learn more about it HERE.

2/1/2012 - The WB4IUY 10m repeater on 29.620- is off the air. We have lost the TX site and I am in search of a new place to re-install it. Hopefully it will be back on the air soon. All equipment is operational, it is simply shut down for the time being.

3/1/2012 - The WB4IUY 440 repeater on 442.400- has lost it's PA, for a 3rd time. I am going to replace the entire radio, as there must be something wrong with the circulator or the power control board is going nuts. These things are too cheap to let it drive me crazy :-) It is completely off the air until it is replaced.

9/7/2011 - The WB4IUY 440 repeater on 442.400- has been repaired and is back online.

8/21/2011 - The WB4IUY 10m repeater on 29.620- is repaired and back online.

7/30/2011 - The WB4IUY 10m repeater on 29.620- is down at the moment. A recent electrical storm took out the receiver, and it is now on the bench being repaired. The damage is minor, and should be back up and running very quickly.

7/10/2011 - The WB4IUY 10m repeater on 29.620- is running on driver power only, about 10 watts. The PA will be repaired and have it back up to full smoke very soon.

6/17/2011 - The WB4IUY 440 repeater on 442.400- has lost it's PA, again. This has happened after a local user was running crossband into it for long periods of time. Strange, after running as a link hub for many years, it seems to be having problems with high duty cycle operations, now. I must have overlooked something during the PA replacement. It is again running at VERY low power, around 100mw, at this time.

11/12/2010 - The WB4IUY 440 repeater on 442.400- has been repaired and is back online.

9/23/2010 - The WB4IUY 440 repeater on 442.400- has lost it's PA. It is running at VERY low power, around 100mw, at this time.

11/21/2009 - The WB4IUY 10 meter repeater on 29.620- is now back on the air and running well. It could use a more lofty TX location, but it's running and making contacts again.

3/23/2008 - Some pics and info about the Zebulon site updates are now online. Click HERE to have a look!

3/17/2008 - The new circulator in the 442.40+ repeater has now failed, and was replaced. The problem was traced to a low level transmitter stage that was generating harmonics. The increased current in the circulator was desoldering components. The low level amp stage was replaced and all now seems to be well.

3/16/2008 - The circulator was found to be defective in the 442.40+ repeater, and was replaced.

3/15/2008 - The K4RTP-7 SEDAN node on 145.77, and the W4RAL-7 Packet BBS nodes were re-installed at the new Zebulon site. They are combined into a single antenna with a 6 cavity repeater duplexer and are running nicely.

3/14/2008 - The 442.40+ repeater receive interference problem has worsened. All plug-in boards were removed and replaced, as the problem seems to be associate with vibration. No _real_ repair was found.

3/11/2008 - The 442.40+ repeater has developed a problem with interference when transmitting. An additional pass cavity was installed on the transmitter.

3/7/2008 - An intermittant receive problem on 442.40+ repeater was traced down to bad duplexer jumper cable.

2/25/2008 - The 442.40+ repeater was installed at the new Zebulon site. On-air testing is underway...

2/24/2008 - The new Zebulon repeater site was finally completed and ready for re-installation of the Zebulon repeaters.

6/5/2007 - The new Zebulon repeater site was approved, and is now being assembled and readied for re-installation of the Zebulon repeaters. Much work has to be done, including installation of a concrete pad & weatherproof cabinet, power, cables, paint, etc.

3/5/2007 - The Zebulon repeater site was dismantled, prior to removal of the water tower. We are now in search of a new site for the 10m, 6m, 220, & 440 repeaters, in addition to the packet nodes. Bummer...

1/14/2003 - After 9 months of negotiations, frequency studies, meetings, writing letters, providing insurance info, ate....the management at the prospective repeater site for 147.30 in Wilson has changed hands. New management declined our ability to install the repeater at the new site. 147.30 has been returned to the frequency pool with SERA and the Wilson repeater retired with no ETA for re-installation.

6/8/2002 - More tower work was done at the Clayton tower site today. Click HERE to have a look!

6/2/2002 - The K4RTP-7 SEDAN node in Zebulon was updated to K-net protocol by a WA4MJF chip replacement, and the callsign is now K4RTP-8 to avoid an interference situation when the system drops to emergency power.

6/2/2002 - Several more days of work have been done at the Clayton 147.39 repeater site, including installing lightning protection on the AC power circuits and all antenna feedlines. We're beginning to feel a bit more safe about this new installation, and trying to take as many precautions as possible to avoid another serious strike (if that's possible!).

5/26/2002 - A new 145.01 W4RAL-4 packet BBS node was installed at the site in Clayton, and we still have a bit more work to do on it.

5/23/2002 - The 442.400 is back on the air from a test antenna at the WB4IUY shop. Most of the serious repairs have been completed, and only minor controller work remains.

5/21/2002 - WooHoooo!!! The new 147.39 repeater is now back online. The site was refurbished, a new repeater cabinet was fabricated, new cavities were assembled, a new repeater was constructed, and all is now back as it should be.
5/21/2002 - BULLETIN! New 147.39 repeater is now completed and on the air in Clayton. While it was being constructed to replace the repeater described on the TEARA repeater page, we documented some of it. Want to see pictures of the bulletin described herein? Click =>HERE<= to see it while it was under construction!

5/3/2002 - Man, the Clayton site took a lightning hit last night, and took out the W4RAL-4 packet BBS node, power supply, amplifier, TNC, and did a bit of damage to the antenna system. Someone tell Zeuss to quit picking on us!!

5/2/2002 - A new site has been secured for the 147.30 repeater in Wilson. Decent sites are hard to come by, and we're surely thankful for this one. Lots of stuff had to be done to determine compatability, including an intermod study involving a wide range of frequencies. More on this site will be posted later.

4/26/2002 - The old 147.30 repeater, duplexers, antennas, and assiciated hardware were removed from the Wilson site and returned to the WB4IUY shop for repairs/updates, prior to relocating to a new site. Whew, that thing is HEAVY!!!

4/19/2002 - A problem arose in the messaging system on the 147.39 repeater and was corrected.

4/12/2002 - The last of the 147.39+ cavity cabling was completed to allow cohabitation of the site with a packet node on 145.01. Sometimes, things that seem simple on the surface....well, you know :-)

3/30/2002 - Testing was performed at a possible site for an east-bound packet BBS node today. Much site noise proved the site unusable, but a plan was assembled to hopefully work around this...

3/25/2002 - The W4RAL-7 bbs Packet Node on 147.54 developed a transmit power amp problem. Radios were swapped out, and an additional outboard PA was installed.

3/6/2002 - The 10 meter repeater's transmit site seems to have developed an an intermittant antenna problem. As a result, UHF noise is generated that blocks the link rx. An additional low pass filter was installed on the 10m tx, and that seemed to be a reasonable 'patch' for the time being (until we can get up the tower and locate the antenna problem).

2/23/2002 - The 10 meter repeater's receive site controller thumbed it's nose up at me today, and required the replacement of a timer chip. All is once again well with 29.620-.

2/19/2002 - The 10 meter repeater's transmit site power supply is showing it's behind. It was revamped today, and all seems to be well again.

2/14/2002 - The 10 meter repeater is having some aches and pains after being off of the air for some time. A bit of trouble arose in the amplifier, but that was repaired today and everthing is running again.

2/10/2002 - The 224.80 220 mhz repeater is getting a synthesizer overhaul. Much work is yet to be done, as this repeater was also a fatality when the 10m repeater was struck by lightning.

1/4/2002 - Now that it's cold outside, I've slowed down with other activities and am back on the repeater projects... Many things are underway, including new packet nodes, repeater repairs, etc. The 10 meter repeater is now back online, the 442.40 and 224.8 repeaters are getting a facelift, a new BBS packet nodes are under way for Rocky Mount and Clayton on 145.01, a new SEDAN node is underway for Clayton on 145.77, and the 147.30 repeater will be undergoing a move before warmer weather returns....

The following activities occurred on April 6 and 9-11, 2001....
Once the Repeater's PA problems were corrected, Steve and I set out to begin completion of the control system. Part of the control system is built from a refurbished S-Com 6k repeater controller. The original 6k, in use 2 repeaters ago (what a way to measure time!) in Clayton, was almost completely destroyed by lightning in 1996. I tossed it to the side and almost wrote it off for trash....until I ran across a ham on the internet who had another 6k with problems. After purchasing it, I was able to build one working unit from the two failed controllers. These are fairly expensive units, costing over $600 when new...so I felt it was worth the effort to repair (if possible).
Two Digital Voice recorders were pulled from salvage and repaired for storing the longer messages planned for the repeater. These messages will inform users of VE Session info, describe the TEARA repeater network, remind users of the Nets and Meetings, etc.
DC Blowers were added to the repeater to additionally cool the Power Amplifier, Voltage regulators for the power control circuitry, and power rectifier assembly. These are areas where we've had heat related failures in the past, so we thought we'd be a bit ahead of the game to add additional cooling. DC blowers were chosen, to provide cooling protection during periods of time when the repeater may be operating on DC backup power (no AC power).
Backup batteries were purchased and installed on the Digital Voice Recorders, to retain the voice messages during power outtages. In the past, volatile memory was used in this aplication, and consequently caused me to make a lot of unnecessary trips to Clayton to reprogram things.
The audio interfaces from the DVR's were completed, as well as all of the associated controller interfacing. These messages will play at predetermined intervals, including the initial ID period. A control unit is being designed and fabricated as of this typing, that will sequence various messages to the transmitter, and provide an interface for a digital voice clock (for time of day announcements) and the UHF link radio.
A Radio Shack talking clock is being gutted and modified to provide remote time of day announcements over the repeater. The repeater will automatically 'speak' the time of day at the top of the hour. In addition, users will have an access code allowing the time of day announcement to be requested at will. Another talking function being interfaced to the repeater is the initial ID'r. The initial ID is usually the first message to be played when the repeater is 'awakened' from sleep. This is being built from the electronics originally used in a talking greeting card by Hallmark.
Click =>HERE<= to see pictures associated with work done on April 6 and 9-11.

The following activities occurred on April 4/5, 2001....
This is another "heads up" on another large amount of work completed on the 147.39 repeater... on Wednesday night, 4/5 (also early AM and lunchtime 4/5!), another major leap towards the completion of 147.39 was made. In recent days, I've been testing the rx sensitivity of the repeater's receiver when in "repeat" mode. The receiver is very sensitive, but would often become desensitized when the transmitter was online. Lots of testing was performed on the duplexers, transmitter, exciter, etc, in an effort to isolate the problem. Finally, it became apparent that the transmitter was intermittently generating wide band noise and exhibiting some instability in tuning.
Late in the night of 4/4, I decided to replace the transmitter's PA (power amplifier) assembly. On 4/5, Steve KD4WIW and I met to formulate a plan and decide what we'd use for the PA. We were all set to pull the entire RCA transmitter (exciter) and PA, and replace it with a 100 watt Motorola Micor (requiring the modification of the Micor, a lot of hardware and electrical modifications, etc) when we were able to locate an exact replacement RCA Series 1000 power amplifier.
Steve, Tim, and I began work last night around 7pm, and by about 11:30pm, a new power amplifier was installed and tuned. The wide band noise problem is now non-existent, and the repeater rx/tx performance in "repeat mode" is what we were hoping for.
Now that the RF troubles seem to be resolved, we're moving forward to complete the interface of the various peripheral devices (the remaining voice messaging equipment, voice clock, weather radio, ac power detector, dc blowers for emergency power cooling, and UHF link transceiver).
The repeater is online at my shop for continued testing and work. Please use it as much as possible, to help me "shake out" any more bugs than may exist. The recent use has been invaluable to me, and was one reason the wide band noise became so apparent. Signal reports have come in from KB4ZMB, AC4UD, KQ4MS, KE4PUV, KD4UAI, K4CMH, N1GMV, KG4ENL, KD4WIW, WA4MJF, KE4VNX, WB4VOD, and others. Thanks for the help!
I've taken many photos of the ongoing work, and will post them on the website ASAP for your viewing enjoyment :-)
Click =>HERE<= to see pictures associated with work done on 4/4-5/01

The following activities occurred on April 2, 2001....
Lots more work was done to 147.39 today, in light of the scattered showers and such. Boy, this has been a busy weekend for repeater related work! Steve KD4WIW, Tom KE4NGH, Tim Richards (fellow Vulcan rider who is interested in ham radio), and I spent the day working on the repeater.
Modifications were made to the last voice message recorder, bracketry was fabricated for the message recorders and they were installed, permanent mounts for the controller were fabricated and installed, the receive preamp was mounted to the cabinet, lots more wiring was completed in the cabinet, rx and tx ports were installed through the cabinet, a new ac power distribution system and duplex receptacle installed inside of the cabinet, terminal strips were installed for various accessory connections, binding posts were installed for the battery backup connections, a new double shielded cable was fabricated and installed between the preamp and repeater rx, an audio delay board was installed in the controller, etc.... There is still a bit of work to do, but things are moving along pretty well.
I took some photos, to be posted on the website in a day or so. The repeater is running on a test antenna, a bit higher up now. Please have a check and see if you can hear it in your various locations.
Click =>HERE<= to see pictures associated with work done on 4/2/01

The following activities occurred on April 1, 2001....
4/1/2001 BULLETIN! Much new work was done at the Zebulon site in April of 2001. Wanna see it? Click =>HERE<= to check out part of the picture archives on this work.
Steve KD4WIW, Tom KE4NGH, Tim Richards (prospect for the amateur service!), Jay KQ4MS, and I were doing tower work all day today in Zebulon. We climbed up and down the Zebulon water tower waaayyy too many times to be fun, hehehe. I'm sure I'll be sore tommorrow! We climbed up to 150 feet, pulled up a lot of gear, swapped out a defective UHF antenna on the 442.400 repeater, removed a 220mhz antenna, rerouted a bunch of stuff for the KQ4MS-3 APRS node and W4RAL-7 Packet BBS node, eliminated a triplexer that was causing a little trouble, installed some new jumpers and replaced some leaky connectors and vapor seal, installed 2 new antennas (for the 29.620 and the 53.07 repeaters), about 400' of feedline, secured a bunch of cabling all over the tower (and I do mean ALL OVER!), cleaned up inside the repeater cabinet and pulled a bunch of needed service on the voice and digital systems (along with MUCH rewiring), and called it a day long after dark.
Things are progressing on the 147.39 repeater. I've gone through the duplexers and repaired/returned them (the lightning hit damaged one of the cavities). The receive preamp is rebuilt once again, and now installed. Much of the controller programming is now completed. 4 new voice messaging systems have been readied, and one if currently running on the repeater in test mode. I spent most of the day on Friday, working on a desense problem caused by wide band noise generated by the tx, but now have that corrected. Tim and I tracked down an intermittant problem with the tx on thursday night, and a good bit of mechanical work was done preparing and mounting hardware in the cabinet. The system is beginning to resemble a repeater, and is now very stable on frequency. Probably, Sunday night, it'll pop online from a higher "test" antenna at my qth.
Click =>HERE<= to see pictures associated with work done on 4/1/01

Some of the posts prior to this were not actually bulletins, but rather bits and pieces of history I found from newsletters and such to try and fill in some of the blanks. Much of the earlier work was not well documented...

3/23/2001 - The 147.39 repeater in Clayton was patched with some old mobile MastrPro stuff to limp us by, while I complete the new repeater. It's not so good, but it is working...sorta...

2/25/2001 - The 147.39 repeater in Clayton has finally bit the dust. Damage seems to be beyond repair (looks like a blow torch was used in the cabinet when it had an internal fire in the HV supply. I'm running wide open to get the new repeater finished and installed.

1/7/2001 - The 147.30 repeater in Wilson has gone crazy. A winter electrical storm damaged the controller, and the processor had to be replaced. All is back up and running now.

11/18/2000 - The 442.400 repeater in Zebulon is choking on a rogue carrier on it's input. Fox hunting is underway to locate the source.

7/12/2000 - The 147.30 repeater in Wilson is back up to speed, and the receiver sensitivity issue was traced back to a defective outboard rx preamp.

7/3/2000 - The 147.30 repeater in Wilson took a lightning stricke and is having problems. Have to schedule time to get to the site and make repairs...

4/6/2000 - The 147.39 repeater in Clayton had much work done today to resolve the TX noise problem that has begun to really drive us crazy. So far, so good...

4/1/2000 - The Zebulon site got a lot of work done today. New triband antenna installed, defective 440 antenna removed, and replaced the 220 rptr antenna with a new 10m ant for the 10m repeater receiver.

3/23/2000 - The 147.30 repeater in Wilson had a new PL decoder board installed. Kevin KT4BN took care of the chore and got the repeater back up and running nicely.

3/2/2000 - The 29.62 repeater receive site dropped offline due to a controller failure. The keying device in the controller's output board was replaced, and it is back on the air.

9/8/1999 - The 147.30 repeater in Wilson went off the air. It turns out that a contractor working in the elevator shaft accidentally hit a circuit breaker and shut the power off to it. After a 90 mile round-trip to the site and a breaker reset, all was back up and running.

8/31/1999 - The 147.39 repeater in Clayton had lost output and was very weak. The tubein the PA was replaced, output tuned up, and all is back on the air.

6/25/1999 - The 224.800 repeater took a lightning hit and destroyed the controller. It is offline awaiting repairs.

10/1997 - The 29.62 10m repeater receive site has been moved from Lizard Lick and is now operational at the Zebulon site.

8/1997 - The 224.800 repeater has been moved from Lizard Lick and is now operational at the Zebulon site. Thanks for Jay KQ4MS, Steve KD4WIW, and others for the antenna installation.

7/1997 - The 442.400 repeater has been moved from Lizard Lick and is now operational at the Zebulon site.

6/1997 - Efforts are underway to begin relocation of all equipment from Lizard Lick to the newly approved and readied site at the old Zebulon in-town water tower. Antennas and hardline are installed, and a new battery backup system is being built & installed in the cabinet.

3/1996 - Work is being done to get approval to use a water tower in Zebulon as a site to relocate the Lizard Lick repeaters to. All looks favorable, but more engineering details are to be supplied and more town hall meetings to attend to get all approvals. The Lizard Lick site is for sale, and loss of it is almost inevitable.

9/1995 - Monthly meetings are beginning with the Town Of Zebulon to hopefully get approval to outfit the old IN-Town water tank for repeater antennas and set it up as a repeater site.

7/1995 - The 147.30 repeater in Wilson received a controller firmware upgrade, a custom built power regulator module installed, additional blowers installed, and a UHF link radio system installed. It is finally linked full-time to Clayton via the 442.40 UHF repeater in Lizard Lick.

6/1995 - The 147.39 repeater #2 in Clayton was set to require a PL of 88.5 to access it, full time. A message was included in the voice ID'r to make users aware of this. Much local opposition arose and many felt this was an attempt to "close" the repeater...it was not. It was a technical way of stopping the non-stop kerchunking caused by splatter from wide band military data bursts being transmitted from Ft Bragg on 148.00 (only 10khz above the 147.99 input)

6/1995 - The 147.39 repeater #2 in Clayton was was knocked off the air yet again (!), by another lightning strike. This damaged the power supply and PA, but spare parts were available and it was back on the air quickly.

6/1995 - The 147.39 repeater #2 in Clayton was was knocked off the air for a day due to another lightning strike. There was only a fuse blown, and it was repaired quickly.

2/1995 - The 147.39 repeater #2 in Clayton was was supplied by Tom W4SIS and readied for installation. It was an old MastrPro repeater with a tube-type PA, and worked well. It was tuned up, put on freq with new crystals, and a controller installed. The Clayton site was back up!

1/1995 - The 147.39 repeater #1 in Clayton was struck a death blow by lightning. It was a total loss. Even the cavities had the coupling loops blown off of them.

7/1994 - The 224.800 repeater was placed on the air at the Lizard Lick site. All was running well and coverage reports were coming in.

5/1994 - The 29.620 repeater was placed in operation at the Lizard Lick site. Vertical separation and lower power of 1 watt were used to get it on the air. Split site operation will be a necessity for this repeater to operate correctly.

5/1994 - The 147.39 repeater in Clayton received a much needed tune-up when the transmitter began generating wide-band noise that would desense the receiver.

3/1994 - The 442.400 repeater was placed on the air at the Lizard Lick site. All was running well and coverage reports were coming in.

2/1994 - The 147.30 repeater in Wilson had an external Astron power supply with blowers added to support the Aerotron amp that was installed.

1/1994 - The 147.30 repeater in Wilson had a power amplifier from an Aerotron transmitter grafted in, and it was back up and running at about 50 watts.

12/1993 - The 147.30 repeater in Wilson had the power amplifier to blow up, literally days before the TEARA Christmas party in Wilson. A temporary power amplifier was connected and it was back up and running at 5 watts,

11/1993 - The 147.30 repeater in Wilson is troubled with controller bugs, duplexer problems, antenna problems. We worked at that site several nights/week and every weekend. All was finally resolved.

8/1993 - The 147.390 repeater in Clayton blew the power amplifier, again. It was repaired, and forced air cooling was added to the PA heat sinks.

7/1993 - A repeater site in Wendell (Lizard Lick) was procured and readied for installation of a few member owned repeater systems. Plans are to install a 440 and a 220 repeater, and part of a 10 meter repeater.

6/1993 - A remotely controllable squelch circuit was added to the 147.390 repeater in Clayton, and this greatly helped in controlling "kerchunking" due to tower noice.

5/1993 - The 147.015 repeater in Wilson was finally co-ordinated with the call sign of WA4UQC and changed to 147.30. The co-ordination required an antenna pattern adjustment to null the signal to the south, and to use a PL of 88.5 for access.

3/1993 - The 147.390 repeater in Clayton blew the power amplifier and was repaired.

11/1992 - Another VHF repeater was assembled on 147.015 and installed in Wilson. Plans to link it back into the original 147.39 repeater are ahoof. The frequency of 147.015 belongs to Kirk KK4YP, and efforts are being made to coordinate a frequency for which to permanently operate this machine on.

6/1992 - KK4YP, WB4IUY, and a few others installed a new UHF repeater in Thanksgiving. It is located about 10 miles east of Clayton at about 235 feet on a commercial tower. The frequency is 444.0 and is one of the wider coverage UHF repeaters in the eastern part of NC.

2/1992 - Several night time investigation sessions were pulled at the Clayton site to determine the problems with mixing on the 147.39 repeater that only seem to happen late at night. Tower rectification was found to be the problem...rusty tower section junctions...

Monday, November 26, 2012

FV-101DM VFO to FT-901DM radios

I have a FV-101DM and a FT-901DE (same remote VFO requirements as the FT-901DM and the FT-902 series). I've seen several notes from people who thought they would directly interface, and decided to dig into this and get mine working. After reading the notes around the web, I studied the schematics and realized that they are incorrect and would have 12vdc being applied to the VFO output and the wrong cable being modified for operation.

The FT-901Ds have a totally different interconnection design from that of the 101ZD's. The 101ZD's have two cables between the VFO and transceiver, the 901Ds utilize one. Additionally, the FV-101Z & FV-901DM have a different pinout on VFO port B than the FV-101DM.

After a bit of experimentation, I discovered the FV-101DM can be interfaced to the FT-901DM with a little work, and retain most of the functionality of the FV-101DM's original design. Here's what has to be done:

1- A jumper must be installed from pin 7 of port A to pin 1 of port B on the VFO.

2- The 6-pin cable supplied with the FV-101DM only utilizes 3 wires (with no shielded circuits for the VFO output), as it intends for the VFO communications to the 101ZD to be via VFO port A. For this reason, a new cable with 6-pin connectors must be assembled to connect from the FT-901DM to the FV-101DM VFO port B. Wire the cable, pin to pin (i.e. Pin 1 to pin 1, pin 2 t pin 2, etc). Use a piece of small coaxial cable with the center conductor connecting pin 1 to pin 1, and the shield connecting pin 2 to pin 2. Standard unshielded wire is fine for the other pins.

3- Assemble a power cord to plug into port A on the VFO, to supply an external 12 vdc source to pin 1. Include a fuse link at 250ma to protect the circuit in the event of a problem. Connect the negative of the 12 vdc source to the cabinet of the VFO (there is no ground connection in the socket for port A on the VFO).

That's it! Mine is working great, and has all functionality except the VFO memories can not be programmed from the FT-901DM, but can be programmed from the VFO just fine. This is because there is no feedback path from the FT-901's internal VFO to the FV-101DM VFO like there is with the FT-101ZD.

The FV-101 is a good cosmetic match, and works well with the 901 after these mods. Below is a pic of the reassembled VFO as paired up with my FT-901.


Saturday, October 6, 2012

Get your 160m Antenna up!!

Wow, the band has been nice over recent days. The nights are getting cooler, and the noise floor is dropping. I've been taking advantage of it a bit before work in the mornings, just before sunrise, when the atmospheric noise has been at it's lowest at my QTH.

I've pasted a pic of my band scope in this blog, so you can see. Normally (during the summer months), noise is about 1/3 the way up the band scope and distant signals are almost impossible to hear. During the fall, winter, and spring, noise is lower and DX is abundant.

The first 160m DX of the season for me, was SV3RF on 1.81852 in Greece via 180m inverted V @ 100'. He was 559 in NC. The next morning I worked VK6GX in Western Australia on 1.8215 CW at 11:20z (7:20am est). Same 100w w/Inverted-V. Yesterday, I worked VE1ZZ on 160m CW this morning around 6am. Not great DX, but it was the only thing on the bad outside of the USA in earshot and the band was quiet.

So, put up an antenna for the winter and get on 160. You'll be surprised what awaits you on the "Magic Band"!

Monday, July 30, 2012

Re-Opening my Personal Hamfest!

While cleaning up a bit in my home workshop, I came to realize that I have WAY more 'rainy day projects' than there are rainy days... I've started itemizing parts, radio gear, and test equipment and listing it HERE on my personal hamfest page.

In years gone by I've parted out estate sales, loads of government radio gear, TV shop inventory I'd bought, along with various pieces of radio equipment I had repaired and wanted to sell. I found it much easier and more relaxing than trying to drag all that stuff to hamfests and less trouble than trying to manage a bunch of eBay listings.

I have many hundreds of tubes, all of which have been tested on my Hickok mutual conductance tester. They are a mix of NOS inventory, pulls, etc. I originally bought all of these to supply my own restoration needs for my boat anchor collection, but it got way out of control :-) You can take a peek at some of them HERE .

I'm always looking to improve my work bench on the cheap, so I'm constantly picking up used test equipment to restore. As a result, I also have a bunch of pieces of test gear in various stages of restoration. Some good, some not so good, some just for parts. You can see some of it HERE

I'm also always looking for that 'next piece' for my boat anchor collection. I list the items I'm looking for on my hamfest page as well. The inventory that is for sale is constantly changing, so keep an eye on the site and let me know if you see something you need. if so, drop me a note at wb4iuy@eastrc.org .

Sunday, July 15, 2012

Light Duty Rotator? No problem!

I was listening to a conversation on HF between two guys who each had spent well over $1000 for antenna rotators, each having less rotator load than myself. I joined into the conversation and both guys quickly told me how I was doing this wrong, why I was doing this wrong, and how my rotator would never hold up the way I have it loaded. So, I'm typing in my blog pretty much what I told them... Suffice it to say I'm cheap when it comes to this hobby. I've been a ham since 1974, and most everything I've had, I've bought used, as junk or "fixer uppers", or built. There is only one rig in my shack I've bought new... Back in 1993, I had my doubts about using a light duty rotator to turn my array. I'd been picking up pieces of salvage or used Rohn 25 & other parts for a couple of years to build my tower, and only had about $300 total in my 105' tall tower setup. I had a big pile of aluminum I had collected from swap meets, salvage from another ham's hurricane damage, and stuff I'd accumulated from helping other folks with their tower setups (read $0 investment). The rotating mass consisted of a Cushcraft A3S, a 5el 6m Cushcraft yagi, 2ea. Cushcraft 17b3 long boom yagis for 2m, and a 15' tall Diamond vertical on top. The problem was, a rotator for this much stuff was gonna cost more than I had in everything else combined, and was way out of my budget. After pondering it a bit, I remembered an experiment I had with an old TV antenna rotator many years ago. I discovered that most of the small rotators use a shaded pole motor (similar in design to that used in small fans and such). Shaded pole motors are neat in that they don't really overheat or fail when overloaded or stalled. I found that if I fed the small TV rotator with a long run of a small gauge rotator cable, there was sufficient voltage drop across the cable when the rotator was stalled to prevent the rotator from overheating. I visited a local radio shop and found a HD-73 rotator by Alliance. This is a very light duty rotator, but unlike some of the cheap TV antenna rotators, it had a feedback pot in the rotator housing for position indication on the control box. So, even if it was slow, the indicator would still display the direction accurately. Many TV antenna rotators have a separate motor that turns the indicator on the control unit and they easily get out of sync if the rotator stalls. A feedback pot is the only way to go...
I made a tower mount for it, installed a bearing around the vertical mast with a home made ice shield, and installed it. Once everything was stacked on top, it was time for the real test. In June of 1993, I found that it took about 75 seconds to turn from stop to stop. As of this writing, 19 years later, it still takes about 75 seconds to make the journey from south to south. It has survived a direct lightning strike that welded the bearings together. I've worn out the direction control switch on the unit and had to replace it. It has been stalled when I'd forget and leave the control box rotating in one direction or another (it is no longer 'spring return' to the OFF position), to the point where the thermal sensor in the control unit would trip. It has run flawlessly while horribly overloaded for 19 years. I've learned that cheap can often be shoe-horned into operation and work pretty good, a little planning makes 'cheap' work a long time, and the HD-73 has got to be tough WAY beyond it's price point!

Wednesday, July 4, 2012

Packet Radio Still Rocks!

On 6/1, I was enjoying working some DX on a Sunday afternoon, when a storm came up. I disconnected everything and shut down. The AC power, cable, and even the local cell phone tower was knocked out.

We have a 'whole house' generator, so I switched over to the it and got the house back up and running, A/C and all. The storm passed, but power didn't come back on. I reconnected my antennas, changed my dx spotting from telnet to TNC, and reconnected to the cluster via packet radio.

Here's a pics of the logging program being switched to TNC mode in the DX Cluster interface and connecting to the packet radio DX Cluster...and the spots were flowing again! Even with the power out and no internet at home, I was DXing and posting spots. The outage even took out my cell phone here, but my old technology still works great!

Monday, April 23, 2012

My FT-901 back on the air!

After looking at my old Yaesu FT-901 in Studio "A" with a failed transmitter for several months, I decided to dig into it this past rainy Sunday and see what had gone wrong with it. I checked the usual things... the 6146's and 12BY7 tubes, bias, operating voltages in the RF cage, etc. All was normal. It was actually producing about 100mw, and all was loading up OK, she just wasn't pulling any plate current above idle, as if there was no drive. I broke out the scope and started poking around a little, and discovered the TX output from the RF board to be waaayyyyyy down. After some voltage drop checks, it looked as if one of the 3SK40L's N-Channel mosfets had failed.

I scrounged around in my Yaesu spare (junk) parts box, and found an RF board from a later model. Mine used the PB-1702, and I had a PB-2154A from a later (newer) model. You can see the two boards compared above, and the component layout (and overall design) to be very different. I compared the pinout on the edge connector between the two in my shop manual, and that seemed to be the same. The old board used two FETs in the mixer, the newer boards uses a diode ring mixer. I started to pull a FET from the new board, but a bit more reading on foxtango.org suggested the newer board would work and was an IMD improvement.

On the left, you can see the new version RF board plugged in for a test, with the red, yellow, and green cables plugged into the top. I plugged the new board in, flipped the switch for a smoke test, and she came alive with full output. Yipee!! All is well, and my old FT-901DE is back on the air with a newer version RF board to boot. Ya gotta love these old rigs for ease of service. My rig is one of the early serial #'s, produced sometime around 1978. Despite it's age, it was one of Yaesu's flagship contest rigs of the day, and still preforms pretty darn good today.


Sunday, March 18, 2012

Russian DX Contest...anybody, anywhere!

The Russian DX Contest is running this weekend. The neat thing about this contest is, you can work anyone, anywhere...not just Russian stations. So, it makes the bands a bit more lively and enjoyable. I'm up at 12:45am playing around on 20m, and surprisingly enough...the band is open from VK to PY to XF, etc. Very pleasant conditions to work with 100w. You can find more about this contest at:



Saturday, March 3, 2012

ARRL SSB International DX Contest this weekend!

I'm finally getting a little radio time again...been working non-stop for the last several weeks. I'm enjoying a little of the ARRL SSB International DX Contest this weekend. It's a great way to pick up a few new countries, make a bunch of contacts, and give the serious contesters out there some points.

You can find more info on this at hornucopia.com and at arrl.org . When I'm on, you can see my operations from "Studio A & B" on some of my cams at WB4IUY Shack Cams

Hope to see you on the air!