[ARC5] 80 KHZ IF

[J Mcvey]

 I thought the later HRO series had 176KHZ IFs, but I found a reference to 1939 Navy RAS National with a 176Khz IFIt was fashioned after the HRO junior?

    On Sunday, February 14, 2021, 1:57:00 PM EST, Roy Morgan <k1lky68 at gmail.com> wrote:  
 
 1) No doubt one such “good book” is the Radiotron Designers Handbook, 4th edition, available at:
http://www.tubebooks.org/books/rdh4.pdf
(Unfortunately I do not have a 3rd edition to refer to.
However, a search in the copy here does not find a discussion of IF frequency choices.


2) A Bliley radio shop instrument called the "CCO Crystal Controlled Oscillator Model 1A" is a very handy bench assistant.  It has switch selectable crystals for:

175, 262, 370, 455, and 465 kc. ". . . the most commonly found IF’s in standard broadcast receivers."
And also 1000 kc for aligning RF sections of receivers.
And an external socket for FT-243 type crystals.

3) The Atwater Kent radio type H-1 from the 1930’s has an IF of 130 kc.

PS: I have for sale a copy of Modern Radio Servicing, Ghirardi, 1st edition, corrected, 1936.


> On Feb 2, 2021, at 11:19 AM, Bob Groh <bob.groh at gmail.com> wrote:
> 
> ...In general, the choice of the IF frequency in a receiver is dictated by (at least in the 'old' days) by the somewhat conflicting needs for narrow IF bandwidths and image rejection - ...
> 
> It get's a bit more complicated than that but I have nattered on for too long already. Some good books out there on the subject.

Roy Morgan
K1LKY since 1958
k1lky68 at gmail.com
Western Mass





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