[Milsurplus] BC-342 N Question

[Al Klase]

I'd be really suspicious of any receiver in which I could not hear white 
noise with the antenna disconnected. - Al

On 4/2/2013 8:43 PM, Glen Zook wrote:
> Some background "hiss" is going to be present in every tube-type receiver that I know of when the audio gain is wide open.  Basically, every tube has a noise figure.  Even solid-state equipment is going to have some background noise with volume at maximum.
>
> Mixer stages often contribute more to the noise than other stages.  But, both the r.f. stages and the i.f. stages are going to contribute to noise as well.
>
> My particular BC-312M has had most of the components, except for the frequency dependent capacitors in the shielded portions, replaced with new components.  There is still a fair amount of noise when the antenna is disconnected and the audio gain and r.f gain run at the maximum.
>
> http://k9sth.com/uploads/Restoration_of_BC.pdf
>
>   
> Glen, K9STH
>
>
> Website:  http://k9sth.com
>
>
> ________________________________
>   From: Laura and Jim <mcenfalz at humboldt1.com>
> To: milsurplus at mailman.qth.net
> Sent: Tuesday, April 2, 2013 7:30 PM
> Subject: [Milsurplus] BC-342 N Question
>   
> Triggers a memory - I have a BC-312-M and there's always a background hiss then in dead air, 200V B+, and the volume is turned all the way up. I seem to recall discussion of "noisy mixer tubes" but can't place where it took place. Any ideas?
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-- 
Al Klase - N3FRQ
Jersey City, NJ
http://www.skywaves.ar88.net/