[ARC5] BC-221s

[Kenneth G. Gordon]

On 2 Oct 2017 at 11:12, Richard Knoppow wrote:

>     Thats the book, thank you. Mine does have modulation, I have to look 
> at it to see which version it is but think its an AK. Its in a wooden 
> case with an AC power supply and a pair of headphones. Has the original 
> calibration book. I no longer remember where I bought it, a local 
> surplus store no doubt, or what I payed for it, maybe $25. It all worked 
> and has needed no repair (he said with his fingers crossed).

I have two -AKs, both in wooden cases, and both work, and both have their original 
calibration books.

I remember I paid $5.00 for one. I think I may have paid as much as $20.00 for the other, 
but it has been a long time.

Both have homebrew AC supplies in them, both of which are well made. Both include a VR 
tube. Although I haven't checked recently, seems to me that they are VR-90s.

One, the one I used the most often up until recently, has some sort of intermittant short in it 
wherein the rectifier tube gets destroyed. I haven't checked that out yet. Kinda weird in that 
no other components in the power supply even get hot. Strange.

Both of them have the trimmer cap for the crystal oscillator "reach-able" from the front panel 
behind a small plate. Both of these are within a few cycles of zero beat with 10 MHz WWV 
after a bit of warm up.

I really like them. I find them at least as stable as any other high quality oscillator. 
Comparing their frequency readout with my good frequency counter (whose crystal oscillator 
is both "oven-ized" and zeroed to 10 MHz WWV within about 1 Hz) shows their accuracy to 
be very good, but I haven't checked the details lately.

I use them to align receivers, setting one at the low end and the other at the high end of a 
band.

I like them a lot.

Ken W7EKB

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