[HBR] Fw: Building a HB-65.... (sort of)

[Hugo W. Catta]

I didn't realize I sent this in HTML format.
Now is in plain text.
Sorry for the inconvenience.

Hugo
AA1XV

----- Original Message ----- 
From: Hugo W. Catta
To: hbr@mailman.qth.net
Sent: Thursday, July 31, 2003 10:51 AM
Subject: Building a HB-65.... (sort of)


Hi, All:

SOme time ago I started gathering parts for an HBR receiver of some kind.
I ended up with a "modified" HB-65 ( 1965 ARRL Handbook ) that is in the
"first picture stage", by now. The components are mounted on the chassis but
not wired yet.
The circuit was changing and evolving as I was finding components. The ideal
was an HBR 11 or 13 but the cabinet that I found could only accept a 8 by
12" chassis, the power transformer yields only 65mAmps, so I am limited to a
7 tubes, HBR-7 ??? :-)  ).
The Bands to cover are 40 and 80 without bandswitches.
The only ( so far) mod to the original HB-65 is the mixer. Instead of using
a 7360 I am using the 6U8A pentode and the triode will be the HFO.
I spoiled a couple of 262Khz I.F. transformers (Miller K-Tran 15-H) while
moving the windings apart as Kees suggests in his fine notes but now I have
four good transformers ready to shunt with 430pf to resonate at 100Khz.
For the first IF I found two Miller 1732.
The only thing that I'll have to experiment with is the BFO coil. I am
thinking on using one side of another K-Tran 262Khz transformer in a
colpitts oscillator circuit and get to 100Khz with added capacitance.
Has anyone tried this?
Also since the IF is 1700, the front end has two tuned circuits (band image)
calling for Miller adjustable coils (4406). How about T-68-2 toroids? What
is the issue (other than non-adjustable cores) with using iron powder
toroids with tubes?

In the next days I'll take some pictures ( as soon I can borrow a digital
camera), and post them.

Thank you in advance for all and any feedback.

Hugo
AA1XV