[ARC5] Receiver sensitivity

[Richard Knoppow]

    Keats Pullen invented some very interesting circuits including the 
common cathode mixer stage. He has a couple of books on the Tubebooks 
site. One book is on using conductance curves to design tube circuits.

On 12/10/2016 8:09 PM, Kenneth G. Gordon wrote:
> On 10 Dec 2016 at 19:44, Jim Haynes wrote:
>
>> I don't know how it compares with more conventional receivers, but the
>> rare Squires-Sanders receiver uses a 7360 beam switching tube as a mixer.
>> And as the receiver front end - no RF amplifiers ahead of it.  Squires
>> wrote an article "A New Approach to Receiver Front-End Design" in QST
>> for September 1963.  Review of the receiver in QST for May 1964.
>>
>> The same front end was adopted by Vic Poor for the receivers made by
>> Frederick Electronics Corp. for commercial/government use back in
>> those days.  His receivers were all solid state except for the 7360
>> mixer front end.
>
> And I have a VERY interesting receiver here which was at one time used by the FBI, God
> alone knows where. It uses pie-shaped devices in which are mounted separate tuned
> circuits for the input and oscillator sides on a rotary "band-switch" mechanism. The input
> stage is a straight mixer. No RF amp.
>
> I, very strangely, s finally offered a manual for this thing by someone attached to this forum,
> who found the manual...in a dump in New York...
>
> All other receivers of this type had had the input tuned circuits destroyed by the FBI to
> preclude "others" from figuring out what frequencies they were using.
>
> Mine is substantially complete.
>
> I'll have to go look at it to give you the model number and maker.
>
> It is a VERY innersting receiver. ;-)
>
> Then, of course, there is the so-called "Pullen Mixer"...
>
> Ken W7EKB
>
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-- 
Richard Knoppow
1oldlens1 at ix.netcom.com
WB6KBL