[Boatanchors] HQ-129X Modifications RF & Mixer

[Bill Cotter]

Greetings HQ-129X enthusiasts!

Have any of you done the RF amplifier and Mixer modifications to 
the HQ-129X receiver as described in William Orr's (CQ Nov 1957 
p103) "New life for the National NC-240D?" This is where he uses 
the low-noise 6SG7 in place of the 6SK7 RF amplifier, and the 
6SB7-Y in place of the 6K8 mixer.

I find the HQ-129X to be quite noisy around 10/15M and thought that 
making these modifications might perk it up a bit. The difficulty 
appears to be in the mixer circuit, specifically rearranging the 
oscillator feedback.

Thanks es 73 Bill N4LG

PS: If anyone needs a pdf of the Wm Orr article, drop me a line.





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Bill Cotter, N4LG              E-mail: n4lg at qx.net
173 Carolyn Lane               Home: (859) 887-5563
Nicholasville, KY 40356-9340   Work: (859) 323-6474

ARRL   ARCI #9878   QRPl #1646   QCWA #29393   FISTS #4535
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