[HBR] Cheap & Easy Selectivity

[bignick at execpc.com]

Ed,

Am I too late?  Can I still get a copy of said
article?

Thanks!

73

KC9KEP



> Edward Swynar wrote: 
>> Hi Again Everyone, 
>> 
>> If anyone is interested, I just finished
scanning the regenerative IF 
>> article from the November 1940
issue of "RADIO" magazine, and would be 
>> more than
pleased to send it along to whomever it is that might be 
>>
interested... 
>> 
>> It's two pages in length---I
reduced the size & converted the files to 
>> jpeg format,
so that they might be a bit easier to download for those of 
>>
us (myself included!) who are still still on dial-up internet service. 
>> 
>> As mentioned previously, this particular
design---according to the 
>> author---goes one step beyond the
simple "...two wires side by side to 
>> achieve
regeneration in an IF stage" approach. Indeed, he says that not 
>> only is the signal of interest boosted in strength by virtue of
this 
>> circuit, but interfering signals are actually reduced
by a corresponding 
>> amount. 
>> 
>> As
anyone knows who has ever tried a regenerative IF stage, this does 
>> not happen by design, i.e. the reduction in signal strength of
adjacent 
>> frequency QRM. 
>> 
>> 
> Eddie, I'd like a copy please. Thanks Gary N9ZSV 
> 
> 
> 
> 
>> Anyway, it all sounds like a
very neat design, albeit requiring the 
>> trouble of having to
wind a scramble-wound coil & installing it at the 
>> base
of the secondary winding of the IF transformer. 
>> 
>> ~73!~ Eddy VE3CUI - VE3XZ 
>> 
>> 
>> **************************************************** 
>> ----- Original Message ----- 
>> 
From: Edward
Swynar 
>> To: hbr at mailman.qth.net ; homebuilttuberadios ; Old
Tube Radios ; 
>> AmRadGear at yahoogroups.com ;
boatanchors at mailman.qth.net ; Welcome to 
>> the Novice Rigs
List! ; antiquewirelessassociation at egroups.com 
>> Sent:
Thursday, August 20, 2009 11:13 AM 
>> Subject: Cheap &
Easy Selectivity 
>> 
>> 
>> Good Morning
All, 
>> 
>> I just ran across a sweet little
article in a 1940 issue of the old 
>> "RADIO"
magazine on a fool-proof way of adding selectivity & gain in 
>> an IF stage that (supposedly) approaches that obtainable with a

>> resonant crystal filter...but without the filter insertion
loss, of 
>> course. 
>> 
>> The design
is rather obscure in that I've never seen anything quite 
>>
like it in any ARRL publication. Suffice it to say that it goes a bit 
>> extra beyond the mere
"...place-the-plate-lead-into-the-IF-can" 
>>
approach of achieving feedback, yet it still looks very
"do-able", and 
>> I plan to incorporate it into my
1929-style 12-tube superhet here. 
>> 
>> If anyone
has access to any of the West Coast Handbooks of the late 
>>
30's, you'll see the design used in the "Super/Ultra Gainer"
receiver 
>> designs described therein... 
>> 
>> Wish me luck! 
>> 
>> ~73~ Eddy VE3CUI -
VE3XZ 
>>
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