Analog Radios more Resistant to Electrical Storms?

Over the years I’ve had a number of radios, both digital and analog. In that time I’ve had a number of damaged radios that were impacted due to (I assume) electrical storms in the vicinity of the QTH of the damaged gear.  I have always used lightening arresters and so forth, and proper grounding, but there is a certain amount of energy that gets into the shack from nearby storms that are not producing any direct hits, but still do manage to produce a lot of ambient energy.

I’ve noticed that the old analog radios seem to stand up to the storm, so to speak, better than the digital ones (now this is anecdotal information that only involves four radios, so it could be insufficient for the making of any conclusions).

In the first case I had two radios hooked up to the antenna and rig switching network, with one being an analog (oldie from the seventies) radio, and one being a newer digital radio.  The digital radio suffered a failure, while the analog radio (the oldie) did not.  The second case was similar, with another older analog radio hooked up at the same time as a second digital radio.  The result was also similar, as the analog radio sailed right through and the digital one suffered a failure.

If you think about it, the old analog transistors would seem to be hardier things than a fet or a logic chip.  The MOS technology builds a capacitor into every device, which may not handle a lot of voltage. Often, they do not.  Sure, some of the big MOSFET power transistors can take higher voltages, but many of the others are very low voltage devices.  Any old NPN analog transistor will likely have a collector-base breakdown of over a hundred volts, and often have a collector-emitter breakdown limit of near that amount.  So, they just seem to be the hardier devices.

I suppose that one could go back to the old tube type radios for even more hardening, but that’s too rustic for me.  I’ll stick with the old analog dogs, that are old but not antique!  I guess I just have a hankering for the old things, and this is just another rationalization for me to collect more of them.

Fixing Stuff: A TenTec 645 CW Keyer

Figure 1: The ball bearing assembly, extracted from the old keyer

The old TenTec Ultramatic Keyer is still used today by many amateurs, including myself. Its Ultramatic keyer mode was born in 1953, and later overtaken by the Iambic A and B modes. I still use the two of these keyers that I own, but one recently needed a repair … In the video shown in figure 2, you can watch a 35 second walk-thru of the disassembly and repair.

Read more about fixing the old 645 Keyer …

A Corsair II

Figure 3A closer look at the Corsair II (left of photo).  Click to enlarge.

The first thing I did with the new-to-me Corsair II was to check the output voltage coming from the TenTec power supply that accompanied the radio.  These old power supplies can suffer from shifted component values over the decades.  It turned out that the TenTec power supply was putting out around 14.5 volts – a shade on the high side.  I took the cover off, and ran the adjustment trimmer down to a more appropriate 13.8 volts.  The previous owner had mentioned a little problem with the display not always working.  I noticed this too – but the problem seemed to go away when the voltage was reduced.

It took a little while to get used to the Corsair II’s pass-band tuning and its other various selectivity features. Once I got the hang of them, I found that …

Read more about the Corsair II …

Triton and Me: Back together Again

Figure 1The Ten Tec 540 is playing love songs again

Four times I courted her.  Three times I dropped her.  This time it’s forever.  Over the years, I’d managed to find myself paired with the one whose songs were so delightful, whose voice stuck in my memory for the whole day long.

Impressionable and easily infatuated, my young mind learned of the CW siren, that seductress of the airwaves.  Long into the night, I listened to her soft messages, sometimes drifting off to sleep with my hand on the key, eventually slipping into one of those sweet dreams of hamdom.

Read more of the Ten tec 540 …

Junk or Joy? Heathkit GR-78 Amateur / Shortwave

Figure 1:  The venerable? Heathkit GR-78 receiver, as it was found in flea market.  

What ham can resist the allure of a piece of vintage gear, sans cover, knob, and a part or three, looking ever like the cartoon character with sprigs of pointy hair wires protruding from it, and connected to nothing?  When we go to ham swap ‘n shops, we brace ourselves ahead of time, lest we not load our trunks with the contents of theirs.  We have time in such cases to revisit the vision of our junk corners at home, and the XYL’s displeasure of same.

But …

Read more Junk or Joy …

A Cloud Warmer for Eighty Meters

cloudburneraFigure 1:  The cloud warmer for eighty meters.  Click to enlarge.

So, on eighty meters my signals were always in the dust. In the fall season, with thunderstorms hundreds of miles away, I had an S6 static noise level, with crashes above that.  It was enough to drive me back to the forty meter CW band.  The problem was twofold.  First, I had a very “loaded” 80 meter attic dipole, and secondly, it was a dipole.  Hence it was poor to begin with (being both loaded and in the attic), and a great static noise scooper (like all dipoles are).

Read More …