Monday, November 10, 2014

APRS+SA on old 386

I like to use things until they're worn out, shot, kaput...I have an old computer in my shack from 1994 a Pionex 386 running Windows 3.1. For abt 20 years, it has been running DOS APRS. For many of those years, it was a stand alone APRS station, lacking many of the things that newer APRS stations have.

A few years ago, I installed Win98. I tried winXP, but this old PC was far too feeble for a newer OS in it's current state, but it runs Win98 just fine. I put it on my home network, and connected 2 TNCs. It did a great job running a local packet cluster RF port on one TNC, and my DOS APRS application on the other TNC. A year or so ago, I pulled the DXCluster RF port down, as no one was using it. The PC was left running only the simple DOS APRS program...but doing a great job at that.

Recently, I decided to see what could be done to "upgrade" my APRS operations with better maps and such. I found APRS+SA was available, and is now has free registration. I already had SA 6.0 (Street Atlas) on this old computer, so the mapping part would be much better. I got it installed, registered, and sorted out for the most part. Wow, what a great improvement it was over what I was running. It can run as an IGate, interface my WX station, sends & receives messages very easily, and the mapping is a huge improvement.

It's not the newest whiz-bang option out there for APRS, but it really gave this old junker APRS station a new lease on life :-) Thanks to Brent KH2Z for a great APRS program that still runs on this old platform!


Friday, August 1, 2014

Grandson of local ham needs help!

A good friend and local ham, Ken Dimaio KF4GOQ, had a grandson born premie, during a family emergency. A horrible story, so sad. Little Paulie's mom had just lost her brother and the stress was more than she could endure..

From Ken:  "Requesting assisted funding for my son and his wife for their newborn premie baby boy. Little Paul was born 8 weeks early under duress circumstances as the baby's mother's brother had just passed, and was being buried the same day as the unexpected birth. Little Paul is stable but as with all premies the future is unknown. Please help, as their medical bills will undoubtedly be stagering with a 6-8 week stay in NICU. Insurance will not cover it all. Thank you all so very, very much."

Their family needs help. Anything you can do is most appreciated by them. Please help with anything if you can, and share.The link to the funding site is:

Ken can also accept donations on behalf of Paulie to his QRZ address of KF4GOQ, in the event someone wants to donate in that way. 

You can also reach Ken via email at:

Sunday, June 15, 2014

Need 2m ops for the ARRL VHF Contest!

Propogation is good on 2 meters for the ARRL VHF Contest, but we need more stations on the air! I just worked a guy who was in the parking lot at Ft. Fisher, NC. I've made contacts on 2 meters with 50 watts to: SC, all over NC, Va, Pa, & De. Most all had good signals, and everyone reported "slim pickins" on 2m SSB and CW due to the lack of participation. Lots of folks are on 6m SSB for the contest. C'mon hams, if you have a 2m SSB station, get it on the air for a while. The ops on that band need your contacts.


Sunday, June 1, 2014

Field Day Near You!!

Upcoming Ham Radio Field Day operations are June 28–29, 2014. The following locator might help if you 're a ham and looking for a local Field Day site to participate at, or if you're not a ham radio operator and are interested in ham radio. Find a site near you and check it out! Here's the link to the Field Day Locator:

Want to know more about Field Day? The ARRL has put together a little .pdf file about it, and you can find it here:

Sunday, May 4, 2014

Info on Icom IC-756 CI-V repair...

I made these repairs in September of 2013, but a post this morning from another ham with the same problem prompted me to dig up the info and post to hopefully help others with the same problem.

My Icom 756 (not pro model) lost it's CI-V port from energy induced into the CI-V cable during a near lightning strike. I've read where folks have found the problem to be the transistor pair q801 & q802. This is a buffer circuit on the CI-V port input on the rig, prior to the processor. I found them on the schematic and ordered those in. VERY cheap, only a couple of bucks. My problem was, I couldn't physically find them on the main unit board. All of the pdf's I found online are far too blurry to see the part...

I was referred to Scott Malcom at MTS. He was a tremendous source of help, and sent me a couple of pics of the main poard with the parts I was looking for, circled for my ease of location. Super nice guy, really knows these rigs, I'd recommend him for service if you need to send your rig somewhere for repairs.

I replaced q801 & q802. I tested all of the smd resistors in the circuit and found them to all be OK. Once I got the CI-V port transmitting data (nice TTL level data seen on a scope), I tried every possible combination of baud rate setting on the USB port, the rig, and the software...but nothing worked. I verified the rig address (50H), and everything was OK. Really had me scratching my head...I pulled the rig apart 4 times while testing voltages and ruling out problems, bit by bit.

I used a little breakout board and level converter I borrowed from a local ham friend, and went directly from the DB9 com1 port on the computer and could get things to talk. I had installed the drivers associated with the USB CI-V replacement cable I got from Kawamall (same folks the previous cable came from), but it would not talk, no matter what. I got an email from Clint W5CPT that directed me to this link for drivers:

I found, running winXP, the drivers sent from Kawamall with the level adapter cable were a version that was not compatible. I downloaded ver from the link Clint sent over, installed them, and all is now well.

Thanks for the help and feedback from everyone, especially Scott Malcom for assistance locating the transistors on the main PCB and answering several questions and giving his opinion, it helped me work my way through this process and get my rig up and running again.

I've uploaded the bits that might help someone else with a blown CI-V port like I have, and you can find them at:

By the way, I use the ribless programming cable from Kawamall on eBay for my CI-V interface, instead of the Icom CT-17. It works on most all Icom rigs and only costs only about $20.Lastly, I'd recommend, when you disconnect your antennas for protection from an electrical storm. also unplug the CI-V cable from the rig :-)


Monday, March 17, 2014

A New CW Keying Control for Studio A...

For some time, I've been wrestling with routing the CW-to-Computer Interface,  the Straight Key, and the keyer to various rigs, depending on the rig/band I was working. I finally decided to do something about it. I built a little CW Keying Control box in one evening, totally from junk box parts. This allows me to use my keyer, CW keyboard, and any straight key with any rig in the shack. No more plugging/unplugging cables when I switch rigs. I discovered that I had to build a little interface for the IC-211, so I just enclosed it in shrink wrap and tossed it behind the rig.

The internals of the CW Keying Control are pretty simple... A 3 position rotary switch, a pair of 1/4" phone jacks for the CW-Computer Interface and external keyer interface, .01uF cap to minimize key clicks, all in an old Radio Shack enclosure that was re-purposed from a previous project.

The IC-211 @M SSB/CW rig has a goofy keying circuit that doesn't provide enough unkeyed voltage at the CW jack to allow switching by the 2N2222 transistor in the computer interface. I built a little one-off interface to take care of those keying duties, and enclosed it in a piece of clear heat shrink tubing, since it was dedicated to the IC-211 and was going to be installed behind that rig.

The control box was finished in about 1 hour, complete with a re-purposed knob from an old junker and some High Tech Redneck labeling. Even the 1/4" phone plugs were all re-purposed from various bits of scrap around the shop...notice how each is a different style.

I installed the control under the 1st shelf at the operating position in Studio A. It looks right at home with the other home brew interfaces and vintage items that are mounted there for ease of operating.

Once everything was tested, I got on the air and put it to use. Wow...what a difference such a simple accessory can make in your shack. I don't know why I waited all these years to 'get around' to building this, but I'm glad I used this rainy afternoon to build this little piece!

Here's a rough schematic of the keyer interface I designed and built for the Icom IC-221 2m SSB rig. The CW keying circuit in that rig has to be pulled down to 0vdc to work correctly, and the solid state device in my computer interface only pulled it down to .6 vdc. I whipped this up, wrapped it in clear heat shrink tubing, and tossed it behind the rig. Works great!

Sunday, March 16, 2014

W2ENY AM Filter for the IC-756

I've been looking for an AM filter for my IC-756 for many years, and just stumbled across a filter from W2ENY. I think he used to offer these, and went out of production for some number of years. He has brought a limited number of these back for sale. I emailed him, he replied almost immediately that he still had some, and I ordered one. I'm happy to have finally found one of these babies. I work AM from time to time on 160 thru 10, and usually operate one of my boatanchors due to the w-i-d-e passband on AM. His page is:
I received the 6khz AM filter from W2ENY for my IC-756. The instructions were EASY to follow and the mod was quick and simple. I LOVE it! I've been working AM on 80, 40, and 15m with the 756 and have great selectivity on AM. I replaced the 15khz filter in the 455khz I.F., and have noticed no issues with working FM on 10m, listening to broadcast stations, etc. My 18 year old IC-756 is now perfect in my opinion, and everything is working great. This is the filter the rig should have come with from the factory, as all modes are well behaved, now.

UPDATE: 3/16/14... After using the filter for about a year, I felt the need to make another change. The instructions from W2ENY mentioned to replace the 15khz filter in the 455khz I.F. with the 6khz AM filter. I found, when operating AM on 10m, it is desirable to have access to the 15khz filter to open up 

the receiver a bit for the broadcast audio often heard on AM. Also, when working 10m FM, the 9khz filter in FM narrow is a bit too narrow for good audio and clipping would occur. I never found a need for the 9khz filter in AM or FM operation, but I constantly found the need for the 15khz filter. So, I reinstalled the 15mhz filter and installed the AM filter (6khz) in the place of the 9khz filter, and all is now well. Just my $01 worth, but it sure works out better at my QTH in this configuration. 

You can visit my website at for more mods for the IC-756 pre-Pro (analog) model, and lots of other ham radio stuff :-)  

Thursday, March 13, 2014

Updated 60m Mods for the Icom IC-756

 60M for the IC-756 Standard

Modifying the ICOM IC-756 Standard (non-Pro model) for 60m takes a little work, but it's worth the effort. First, the transmitter has to be opened up for general coverage operation. That's pretty easy. Here's the info for the first phase of the modification...

Remove bottom cover. On the MAIN board you will see IF filters and a daughter board (DSP filter) on the right side. The W805 jumper and IC803 chip is located under the DSP board. You have to remove the DSP board (carefully) and look for the part labeled IC803 and the line of SMD jumpers (little green parts). Locate and unsolder the W805 jumper. Re-Install the DSP board and put the bottom cover back. Below is a drawing of the chip & jumper locations, a pic of the circuit board, and a pic of the jumper on my fingertip after removal.

         [W801]     |               |
         [W802]     |               |
         [W803]     |    IC 803     |
         [W804]     |               |
REMOVE== [W805]     |     CHIP      |
         [W806]     |               |
         [W807]      ---------------


When I first modified the processor, as I had seen numerous bits around the web for adding 60m, it worked 'OK', but would only put out about 50% power on 60m. I found that the band matrix is setup to use the 80m low pass filter up to 6.0 mhz, where it transitions to the 40m filter. Another ham I was talking to on the internet had the IC-756 Pro II and modified his for 60m coverage as I did, and had the same problem with low output power. He had access to some filter design software, and modeled the 80m filter to see where the problem was. He came up with a few capacitor changes to alter the upper end of the filter response to fix the problem in the Pro II. I checked the manuals and board layouts against each other, and while the filter units in the standard and Pro II are physically a little different, the circuit was the same. I ripped mine apart tonight and dove in. Change C7, C66, & C69 to 180pF disc. Change C15 to a 270pF disc. This moves the knee of the filter from 5.25mhz to 5.6 mhz. The end result was awesome...full power right up to the edge of the 60m band and no purity issues. One of the pics here is the filter as modeled in software, the violet curve is before mods, the white curve is after mods. The other pic is of the filter unit.

One last note...the internal antenna tuner isn't mapped to work correctly on the 60m band, but the rig works great with an external antenna tuner or with a resonant antenna. Hope this helps some of you with your 756 to enjoy 60 meters. The filter mods will also work with the Pro II once you use the appropriate mod for general coverage transmit. Many thanks to W6FM for the filter model work!


Monday, February 17, 2014

Hy-Gain Hy-Range 1

Another one out of the junk pile... Hy-Gain Hy-Range I. This is the CB I had in a '61 Chevy pickup, back in the late 70's. I picked up another for parts up at a swap meet somewhere, been in my attic since around '93. Bad channel selector, blown lamps, broken wires in the mic cord, bad speaker, rusty cases. Finally finished it, probably wasn't worth the effort, but it's a nostalgia thing for me

Found a little info about Hy-Gain. Looks like this might have been made before 1975, since the Hy-Gain III came out in '75. Here's a little info in the radio museum...


After... I have this mounted on a bracket near my workbench, in operation most days. 

Saturday, February 15, 2014

Johnson Messenger III

This is an old Johnson Messenger III I picked up at a swap meet. I had one like this on the air, back around 1977 or so. I plan to restore this one at some point, so I started this page to build on when I get to it. 

Friday, February 14, 2014

Midland 13-862B

I cleaned up this old Midland 13-862B CB mobile rig and got it back up to speed. Typical stuff, lamps, cleaned the controls, cleaned it well, alignment. Nothing special, but kinda special to me. It was my mom's mobile back in the mid-70's, when she dispatched for my dad's plumbing & heating company over CB radio. It's been in the attic for probably 20 years or more.




Tuesday, February 11, 2014

Robyn 240D

These are pretty cool little radios. All tube-type, except for the PLL circuitry for frequency synthesis. A friend picked this rig up, and it needed some help. Lots of little problems needed attention, but nothing major. There's practically nothing published on this rig for mods (except for one bogus mod that is all over the web), so I set out to comb through it and fix a number of problems and upgrade / improve a few things. You'll need a schematic or Sams Photofact to locate some of these items, but the work is pretty straightforward. 

Power supply & modulation issues : 

Once working correctly, I noticed this rig (and another my friend brought to me) lacked low frequency response in the transmit audio chain, and didn't have enough headroom in the power supply to allow for 100% positive modulation peaks. Negative peaks were 100% easy, while positive were clipping at about 80%. Here's the list of changes...

1- Install a .5uF 25vdc cap from pin #3 on V6, to ground. Keep leads short. + terminal of cap to pin #3. 

2- Bypass R27, 100 ohm resistor in the 278vdc source, this raises it to about 290 vdc.

3- Lift one end of R28 1K 5W and install a 150 ohm 5W resistor in series, or replace it with a 1150 ohm 5 watt resistor. This restores the 211vdc source to the correct voltage, after the mod in step #2 above. Actually, it raises it from 211 to about 218, and improves the rx sensitivity. More on that, later...

4- Relocate C905 1uF 160v cap from across R906 1K, to across R904 6800 ohm. (-) of cap to the L907 end of R904.

5- Bypass R906 1K. 

6- Change C601 to .1uF 500vdc disk

Receiver sensitivity: 

In step #3 above, I stated to lift one end of R28 1K 5W and install a 150 ohm 5W resistor in series, or replace it with a 1150 ohm 5 watt resistor. This restores the 211vdc source to the correct voltage, after the mod in step #2 above raises it to about 225vdc. This restores the primary receiver strip voltage (normally about 211vdc) to about 218. I have many ham band receivers that place 230vdc or so on those same tubes, with no long term effects. This simple mod improved the receiver sens from .5uV @ 10dB SINAD, to about .3uV @ 10dB SINAD, a very noticeable improvement.

The following changes brought the receiver sensitivity up to better than .1uV @ 10dB SINAD.

Change R106 from 47K to 220K

Change R201 from 680 ohms to 1200 ohms...

Install a 56k resistor in parallel with R303 (100K)

Delta Tune issue: 

I've seen many comments on the web about users having to operate the receiver with the delta tune at about the 3 o'clock position for best reception. I found a 10k ohm 1/2 W resistor installed from the wiper of the delta tune control, to the high side of the pot, will move the varacter voltage to about 4.5vdc and bring the rx center frequency spot on with the delta tune control at 12 o'clock. You could also install a small 15k pot in the same place as the 10k resistor I mentioned, and dial it in that way. The issue is caused by drift in the 15mhz crystal, and padding it results in osc instability...this seems to be the best and most stable approach to correct the problem. 

HEAT!! : 

 These radios run HOT!! I installed a small 12vdc fan inside of the radio, to pull heat out (never blow cool air in, simply pull the hot air out slowly to cool the rig). I picked up the low voltage DC supply for the fan at the high side of R191 10 ohm, and ground directly to the chassis. I installed my fan on the inside, it is nice and quiet, and works great. 

  Instant On: 

Another problem with heat, is where Robyn decided to keep the radio mostly powered up all the time, to give the illusion of it being "instant on". I really don't like this, and want the rig off when the switch is set to "off". This also keeps the rig cool when you're not using it. 

1- Locate the red and brown wires that connect to the power switch. Trace those around the center of the chassis and back to their connection points near the main power socket on the back of the rig. Clip them from their connection points on the terminal strips, and connect a jumper across where they were connected. 

2- Pull the ends of the red & brown wires up and towards the rear power socket on the back of the rig. Locate the (usually yellow) wire coming from the power socket pin #3, and clip it free from the terminal  strip. Connect the brown wire to the terminal strip where you clipped the wire from, and connect the red wire back to the free end of the wired coming from the power socket pin #3

Now, the rig will truly shut down, when you set the power switch to "off", and help with keeping the rig cool.


- Swap the 6BQ5 modulator tube out with a 7189. I use a SOVTEC EL84M for even better modulator performance.  

- Replace the 6GH8A tube out with a 6EA8A tube. It's much more stable over time than those flakey 6GH8A's, easier to locate, and has a little more output for the reference oscillator.