[Milsurplus] BC-9: Earlier and Later Operating Instructions.

[Hubert Miller]

The early set CANNOT have the offset. The "keying" is done by the key in the B- leg, that's all ! NO other change in circuit.
I tentatively take back my comment on the "selected VT-1".  This line was in the manual for the EARLY set and referred simply to finding tubes that would oscillate at all.
I notice the text about the SCR-77-B improvements  says "The modified sets have been developed overcoming these difficulties and are now being issued for service trial."
( page 201 ).
We do not know how the "service trial' turned out ! Can we really assume it was a success ?
Dave, does the dial resolution make possible a marking of "where to retune to, for transmitting" ? 
-H 

-----Original Message-----
From: Kenneth G. Gordon [mailto:kgordon2006 at frontier.com] 
Sent: Sunday, February 12, 2017 4:58 PM
To: Hubert Miller <Kargo_cult at msn.com>; milsurplus <milsurplus at mailman.qth.net>
Subject: Re: [Milsurplus] BC-9: Earlier and Later Operating Instructions.

On 12 Feb 2017 at 21:30, Hubert Miller wrote:

> The later instructions certainly give no indication of anything like what you're experiencing.

Neither do the earlier ones for that matter.

> You  don't suppose this has something to do with the hand-selected, 
> "one in ten or fifteen" VT-1 tubes that will work in the RF slot ?

That was what I was wondering too.

BTW, David, what is the purpose of the 20 volt source and the resistor, pot, and S-1?

Also, in Mike's schematic, where is the filter "F"?

I am going to dig out my #30s, build a clone of this thing, and see what I can make of it.

>From the similarity of the circuit AFTER the oscillator tube, I suspect that the two transformers, T-2 and T-3 are simply common 3:1 transformers. Anyway, that is what I intend to use there.

Ken W7EKB

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