[HBR] HBR-11/2000. Comments?

Tuchueh7 at cs.com Tuchueh7 at cs.com
Thu Jul 13 00:20:48 EDT 2006


After spending the last couple years collecting parts (including the 
Eddystone 898 dial) I have decided to begin construction. I have begun to think about 
layout and have
breadboarded some circuitry. In this first letter I will discuss the tube 
line-up. One major break is instead of plug-in coils, toroid coils and reed 
relays. Here's the dope:
1) Double tuned critically coupled preselector
2) 6ES8 Pullen mixer (ala 75A4 mod on the Web)
3) 6DJ8 1st local oscillator, Vackar design
4) Pair of Miller 1731 link coupled coils (diode DBM in between for noise 
blanking)
5) 6AR8 sheet beam single balanced mixer (like the 7360)
6) 6xxx xtal 2nd local oscillator
7) Two Miller 710 IF transformers (Can you believe I found 5 of 'em for 
free!!!! thanks to
       some great generous folk from the Lake Erie Boat Anchor group)
8) 6EH7 IF amplifier (lots of shielding)
9) One Miller 710 IF xformer
10) 6EH7 IF amplifier (lots of shielding)
11) One Miller 710 IF amplifier
12) 6BN6 product detector
13) 6xxx xtal BFO (98.5 kc. and 101.5 kc) maybe
14) 6xxx infinite impedance detector for AM
15) AGC will be solid state - there is a lot of potential for creative design 
here
16) 5879 low noise pentode 1st AF with lots of negative feedback
17) 6CW5 power amplifier (lots of audio power is important)
18) 190V 200mA power supply, the iron is Triad hermetic isolation transformer
I will post pictures as I proceed. So thats the story here at KC8LTD for now.
73's from Barney


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