[Milsurplus] 102E receiver comparison GRC-9

[mac]

On Jan 11, 2012, at 10:26 PM, Hue Miller wrote:

> Current 'Electric Radio' has article on China 102E receiver.
> Sez stability of both HFO and BFO are superior to GRC-9.
> Why is this, anyone?

I have 3 GRC-9s and have been running them regularly for years.
Have never run any tests but have always found them to be more
than sufficiently stable to communicate effectively with other '9s and
related equipment of the period.

> I also see an article on a BC-106, GRC-9, 102E power supply,
> that instructs to adjust GRC-9 xmtr filament to 6.6 volt.
> Since the tube operates perfectly well at 6  volt, isn't this a
> longevity hazard to the scarce 2E22 bottle?

Six (6) volts is certainly enough.  Loooong power cable maybe?

> Also the HV supply seems to depend a whole lot on capacitor
> charging toward peak. It uses a 750 vct xfmr with fullwave
> 2-diodes with capacitive input. I suppose that would put it up
> around 450 volts D.C.    I would have used a  550-600 volt
> xfmr in a 4 diode bridge. Old school.

That was the xformer he had handy in his junque box....

> If the GRC-9 second IF was a 1L4 instead of the 1R5 IF/
> BFO dualpurpose, would the IF section have greater gain?

Maybe, but the performance with the 1R5 more than satisfactory.

Dennis D.  W7QHO
Glendale, CA


> -Hue Miller
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