WB4IUY

Thursday, March 16, 2017

Hallicrafters SX-42 in da house!

I picked up an old Hallicrafters SX-42 at the Charlotte Hamfest. I had one of these back when I was a novice in 1974, and sold it in the early '80's. I've regretted it ever since. It's not that it was a great receiver, but I do have a soft spot for it. I was fortunate enough to get a spare parts rig and the matching R-42 speaker with it.

The SX-42 was Hallicrafters 'Top Of The Line' received in 1947. It sported crystal phasing and allowed for up to 6 increasingly tight stages of selectivity. By today's standards, it's a poor receiver for single signal CW operation. It is, however, an AWESOME receiver for AM signals from the ham bands or SWL. It operates from 535khz to 108 mhz in AM, CW, and FM. My intention is to pair it with an AM transmitter for use on the 160 meter band.

I got it fired up fairly easy, with very little work. I plan to totally recap it, implement the service bulletins to protect the band switch and fix other things, and bring it back to new cosmetically. Here are a few videos of it in operation, fresh out of the mothballs (spider webs)...






Receiving on 3.875 AM...





Receiving on 1.885 AM...





Receiving on 94.7 FM broadcast...

Dave WB4IUY
http://www.WB4IUY.net





Wednesday, February 22, 2017

AM Rally : Aprtil 1-3 !!!


The AM Rally is coming, April 1st through 3rd. This event will be a great opportunity to work folks on rigs from Vintage through SDR... All technologies welcome! It's more of a social event than a contest, but will be loads of fun for all interested in the AM mode. Be sure to check out all the info online at http://amrally.com/ and check in on the air and enjoy the camaraderie between all operators of this neat, high fidelity vintage mode, with whatever you have to operate AM on! See you there!

Dave WB4IUY
http://www.WB4IUY.net




Saturday, January 28, 2017

160 Meter CW Contest this weekend 1/28/17

Wow, I love this contest. I'm not a really serious contester, I almost never turn in my scores. I enjoy contesting, just the same. It's a great opportunity to pick up new states and countries needed on a certain band or mode, test new antennas and equipment, etc. This contest is very simple, and the rules can be found here:


http://www.hornucopia.com/contestcal/weeklycont.php#7317 


When I hear folks say things like "CW is Dead", I can't help but be amused. Here's a couple of pics from the lower 25khz of the band, on the band scope of my Icom IC-756...






I worked a couple of hours this morning before work, and made a BUNCH of contacts all over the USA and Canada on my new 160 meter "low-pole", low altitude zig-zag dipole. I put this temporary antenna up to keep me on 160 over the winter, while working on my tower rebuild. It's only about 65' up, in a sort-of inverted-V configuration, with the last 30' of each side about 6' up and "zig-zagged" from tree to tree in the woods to get the full length in. I've worked into Europe, Africa, South America, and all over North America with this silly set up.

Anyway, I hope to work you on 160 this weekend. I can hardly wait to get back home from work and get back on!

73 de WB4IUY
http://www.WB4IUY.net




Wednesday, December 28, 2016

Digital modes - Check your gain and ALC...

Many of us work the digital modes like the various PSK's, Olivia, Hell, ect using a sound card interface of some sort. They work pretty darn good in transmit more, if you pay attention to your gain settings and the ALC level of your rig. I hear signals every now and again that are totally whacked out, and most of the time it turns out to be an over driven transmitter from the sound card audio.

I snapped this pic a couple nights ago while operating on 40m PSK31. When the station in Cuba would transmit (his primary signal is on the left in the waterfall), an image would appear abt 700hz up the band (seen on the right in the waterfall). His signal sounded horrible, folks were trying to get him to try turning his gain down, but I don't think he understood what was going on. I'm not picking on him by any means, but you do see a lot of this on the air. I suspect his digital interface was over driving the bejesus out of his transmitter...


Dave WB4IUY
http://www.WB4IUY.net



Saturday, December 24, 2016

Vintage Ham Radio stuff, Hallicrafters, Schlitz...

This isn't much of a blog post, but I wanted to put these things out there for those of you who also love old ham radio related stuff like me. A good friend, Joe (who owns Dit & Dash), found this old unused 1964 Hallicrafters Log Book and sent it to me. Having had my license since 1974, I remember the paper logs and the requirement to log everything, including tune up and test transmissions. I took a few pics of it, it really brings back fond memories.






Next, here's an old 1952 Schlitz beer advertisement, featuring a rendering of a typical 1950's hamshack. This pretty cool, I'm gonna try to turn this into a poster for my hamshack Studio B with my vintage gear.








Thanks to Joe over at Dit & Dash. Here's his Facebook link if you do Facebook:  https://www.facebook.com/DIT-and-DASH-Radios-Antennas-Accessories-285175181595643



Dave WB4IUY
http://www.WB4IUY.net



Friday, December 23, 2016

Computers with Legacy Com Ports, & RTTY Interface

I was stranded an d unable to use my RTTY interface on HF, after a near lightning strike blew the 9-pin serial port on my hamshack computer. Thanks to Matt Harris KD4PBS, he had a spare plug-in card for my computer's PCI slot, to add on outboard serial ports! This provided the 9-pin legacy serial port I needed to get my RTTY hardware back working. Once I found the drivers for it, my old box was back up on RTTY.

For those of you who work digital modes, this is something to think about when you build or buy a computer... While you can use soundcard software to work most digital modes (including RTTY), it typically doesn't allow for hard-keying the FSK port of your rig for true RTTY, and often doesn't allow for hard keying your rig for CW. This means you're unable to use your narrow RTTY or CW filters (since you're usually in USB mod for all digital modes). The receiver can easily get overloaded and the waterfall gets washed out by strong stations on nearby frequencies.

There are almost no USB-to serial port dongles that support the 5-bit stream or reprogramming to 45.5 baud for this, so a USB converter is almost out of the question.

Most HF rigs have a terminal in the aux port on the back of rig for FSK control. Even my old Yaesu FT-901's have dedicated FSK and sharp receive filters for this. The majority of the digital mode interfaces that provide an output for FSK keying require a legacy serial or parallel port on the computer for this, and the majority of computers (esp laptops) have only USB ports and such, no physical 9-pin or 25-pin legacy ports. By controlling my RTTY shift through the FSK port, instead of using RTTY TX audio on USB like in DM780, I can use dedicated programs like MMTTY (love it!!) and work RTTY even in crowed contest band conditions. You might want to buy a computer that at least has an expansion port to allow for a serial port card with legacy ports for this.

Anyway, thanks again to Matthew Harris KD4PBS for the card to get my RTTY station back on the air!

Here's a pic from inside the computer, below the new add-on legacy com port card. This gave me a new com 1 & com 2 port, and disabled the old on-board port that was blown.




Another pic of the board, from inside the PC...


A pic from outside of the PC, showing the new com ports just below the ethernet card. I'm using com 2 for my RTTY interface.


Dave WB4IUY
http://www.wb4iuy.net


Thursday, December 22, 2016

Respect Your Antenna Insulators!

OK, so I got a little re-education on something I had forgotten tonight. Had a little time before dark to tweak on the 40m elements of my hexpole antenna (had to give it a snazzy name, it's just 3 dipole/inverted V antennas fed from the same feedline). Anyway, the 40m portions have been acting goofy and tougher than usual to tune.
The 40m legs needed to be lengthened a bit to move the resonant freq down a little. I made a pigtail, and attached it to the ends of the antenna. I didn't want it just hanging down (not that it matters), so I pulled it across the end insulators, and zip tied it to the paracord on the other side of the insulator. The paracord was a little damp, but didn't give it any thought. It's a synthetic cord, so no biggie, right?

I went in the shack, and checked it at 100w, and found the SWR dip to be about where I wanted it. I kicked on the amp, and loaded it up to 1,499 watts, and noticed the reflected powder to be a little quirky. Suddenly, everything went nuts and I shut it down. I walked out, looked up, and found one of ends of the 40m antenna to be hanging down by the tower, and the guy cord to be on the ground.

Duh, the high voltage points on that type of antenna are at the ends. The damp paracord, was not a good insulator. Arcing at the ends of the 40m elements had literally burned the cord off, flush with the ends of the antenna. I repaired the cord connections and let the ends of the tuning pigtail hang down (not across and against the paracord). All is well.

Gives new meaning to putting some "fire in the wire" :-)
 
Dave WB4IUY