[ARC5] Frequency Meter?

[Richard Knoppow]

     I think I observed something of the sort with my 1001A.  The 
problem is incidental FM, the AM modulator also produces some FM and 
when things are right one sideband will be cancelled. At best the 
sidebands are not very symmetrical. Other generators are similar. The 
ones that do not do this are the more sophisticated ones like the -hp- 
606A and even better the B version and the General Radio 805C, both 
which have very good modulators in them. The 1001A is, to be blunt, a 
rather crude design. It also suffers from hum induced by the power 
transformer magnetic field modulating the electron stream in the power 
amplifier. Nonetheless, GR sold hundreds if not thousands of them.

On 2/15/2017 11:22 AM, Fuqua, Bill L wrote:
> Mistyped I was referring to the GR 1001A
> ________________________________________
> From: ARC5 [arc5-bounces at mailman.qth.net] on behalf of Fuqua, Bill L [wlfuqu00 at uky.edu]
> Sent: Wednesday, February 15, 2017 2:15 PM
> To: Richard Knoppow; arc5 at mailman.qth.net
> Subject: Re: [ARC5] Frequency Meter?
>
>    I wonder if the 805B will also produce SSB like the GR101A.
> Now, that I have gotten your attention, I have to explain.
>    In 1968 I was working in a lab at Tennessee Tech University checking out my
> newly acquired SB8b T-1000 spectrum analyzer. The best signal generator available was a
> GR 1001A. The SB8 T-1000 had a 5 MHz first IF and and a 6BE6 mixer. So you could either
> enter enter a 5 MHz signal and analyze it directly or inject a local oscillator signal and observe
> signals up in to the UHF bands.
>    I tuned the GR signal generator to 5 MHz ( top end of the dial) and observed the carrier.
> All was fine and good. Was getting excited not that I had a my own working spectrum analyzer.
> I then added the modulation, and saw that I had the carrier and only one side band, the upper
> side band.  I was sure  that something was wrong with my spectrum analyzer. I then switched
> the 1001a to the next band up (5-15MHz)  where the tuning cap was at max. at 5MHz and saw both
> sidebands. That was when I realized the signal generator was generating both AM and FM. The
> modulated output tube was acting somewhat as a reactactance modulator and frequency modulating
> the oscillator. The AM upper sidebands were in phase and adding while the lower sidebands were
> out of phase and canceling.
>   Since I have come across several 1001a signal generators and observed they all do the same
> thing. SSB full carrier when set to just the right frequency.
>
> 73
> Bill wa4lav
>
> ________________________________________
> From: ARC5 [arc5-bounces at mailman.qth.net] on behalf of Richard Knoppow [1oldlens1 at ix.netcom.com]
> Sent: Wednesday, February 15, 2017 12:49 PM
> To: arc5 at mailman.qth.net
> Subject: Re: [ARC5] Frequency Meter?
>
>     General Radio 805B.  It appears in the 1939 GR catalog which is
> available from   http://www.ietlabs.com/
>     The GR version comes with a separate power supply which is contained
> in the same cabinet. There was probably an 805A but  don't have
> information on it.
>
> On 2/14/2017 10:38 PM, Fuqua, Bill L wrote:
>>    Looks like the predecessor to the GR 1001a signal generator.
>> Also appears to use external power supply.
>> It is a signal generator. AM modulated with calibrated signal level output.
>> Very nice for the time.
>> 73
>> Bill wa4lav
>
> --
> Richard Knoppow
> 1oldlens1 at ix.netcom.com
> WB6KBL
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-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL