[Hallicrafters] SX-71 Restoration

[Philip Atchley]

Julian, Gary, et al,

Actually, I'M the author of that document, which was originally posted on 
the HCI website and apparently stolen and reproduced without any credit 
given. . .   I suspect that photograph also came from the HCI website.

 Don and NC-183D referred too in the document is my good friend Don W6LRG 
and his receiver.

73 de Phil,  KO6BB
DX begins at the noise floor!

THE BEACONEER'S LAIR:  http://www.geocities.com/ko6bb/
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Merced, Central California,    37.3N  120.48W  CM97sh


----- Original Message ----- 

> Hi Gary,
>
> Your mod is very similar (if not identical) to a mod described here:
>
> http://pcbunn.cacr.caltech.edu/jjb/Hallicrafters/SX71/SoupUpYourSX-71.doc
>
> which came to me from Rodney Bunt (although I don't know if Rodney is
> the author of the document).
>
> Oddly, on the SX-71 Run4 I have, and a Run 3 I sold on Ebay, that 2nd IF
> cathode resistor is already the same value as in the 1st and 3rd. IF.
> Which suggests that this mod was either made at the factory, or by owners.
>
> Julian
>
> GBrown wrote:
>> For those of you that have a SX-71 or those that are going to restore 
>> one.
>> Here is a little tidbit of info that mite make your day. I have just
>> finished restoring a SX-71, from knobs to ant terminal and very satisfied
>> with the performance on the lower HF bands. I thought that the upper HF
>> bands were needing a little more gain. A look at the original schematic
>> shows the cathode resistor on the 2nd IF as being 1000 ohms. CHANGE IT to
>> 270 ohms like the 1st and 3rd IF are. I honestly think your going to like
>> the added gain on the upper bands.
>> Regards,
>> Gary...WZ1M