[Milsurplus] BC-348 modifications

[Hubert Miller]

Well, it's not really our problem, but someone down the line of history, should our world
exist so long, will be faced with the challenge of finding workable tubes. Right now, for 
common tubes, it's no problem at all. Consider that use of valved equipment is so low hours
now that there's virtually no consumption. 
FETs mostly solve the impedances situation. No heat means much less drift, maybe virtually
imperceptible drift. Not to mention heat gradually ruining other components. Or maybe the
challenge of finding another power transformer for your National. 
I bought a couple booklets on ss conversions of typical valved receivers from BC-348 to R-390.
Some of the ideas are worth noting, some hack the original too much for my taste. I am 
slightly suspicious that the simple AGC systems will really work that well for a 1:1 conversion.
But remember 'tubesters' for the Collins line ?

There was some fellow who years back ss'd a BC-611 and then put it on Ebay. I recall it brought 
like $400 and that was about 10 years ago. The conversion was i thought, kind of simple minded
in that it used JFETs all the  way thru. I wonder about the transmitter final though; and i suspect
the output power was much lower than the already low milliwatts. I looked up the guy's qth and
wrote him, more or less politely begging for his schematic; no reply. 

You know what i hate? Being asked to pay $$$$ for some not wonderful tube that has a special 
base so you can't use garden variety subs. The VCL11 tube for the 'People's Radio' cost about $100,
which i reckon is about $90 too much, but try to find a sub ! The German "HRO copy" uses EF series
tubes, which are nothing special, but command a lot more money. There are some Japanese tubes
which are simply unobtanium, end of story. Like some 1.5 volt Japanese acorn types. 

I have enough of a variety of gear that keeping spare tubes has become a pain. But i'm gradually
whittling down the variety. Probably that's part of the attraction of ss; no more spares, except for
a fewer transmit varieties. 
-Hue Miller