[Milsurplus] BC-458-A

[Larry]

Thot i'd play with one of the command set transmitters for a bit to see 
what i could get out of it.  First thing was to check out the 
calibration against the 6200 kc Xtal.  Well it was off by about 12 Kc.  
I set it for a 10 kc offset as it wouldn't go to zero. Surprisingly down 
in the lower part of the frequency range the note coming out of it was 
raspy but the higher in freq. i went the cleaner it became.  Well i 
wanted to use it above 7 mc anyway so this is kinda immaterial.  Ran the 
VFO all the way as far as it would go above & mc and was surprised to 
see it go clear up to 7090.  Didn't realize that it would go that far.  
Not going to use it anywhere but CW mode anyway so another mod 
possibility diffused.

Don't want to modify this unit any at all as it's fully original with no 
extra holes, mods etc.  Wonder if coverage to that far above the 7 mc 
point is normal or is this one an exception?

200V regulated on the plate of the Osc still results in some signal 
variation but again, i've not done anything to the keying circuit like 
eliminating the keying relay for one thing.

Something to play with.

I noticed that when i plugged in a 3 -4 Mc unit that i got no signal 
when tuning to the calibration crystal freq.  Again this is an 
unmodified unit and i'm not intending on doing any mods to it.  Just 
applying some 28V and Osc B+ to see how they work at that point.

Larry
W0OGH