[HBR] Help with old home-brew receiver

[Kevin Berlen K9HX]

At 04:56 PM 3/23/2003 -0500, you wrote:
>In a message dated 3/23/03 12:22:31 PM Eastern Standard Time, K9HX@joink.com
>writes:
>
> > Hi, I am brand new to the list and need some assistance. I recently picked
>up
> >  a old tube type home brew receiver, and hope someone on the list can help
>me
> >  identify it. The receiver uses plug in coils for band switching, and has
> >  several
> >  parts that have been salvaged from an old command set including three 85KC
> >  IF transformers, the 85KC BFO coil and several three section .05MFD caps.
> >
> >  The rig uses an external power supply and the tube line up is:
> >
> >  6AQ5
> >  12AX7A
> >  6AL5
> >  6BY6
> >  12AU7A
> >  6BE6
> >  6C4
> >  6BJ6 x2
> >  1 other 7 pin minature that I can't get the number off of.
> >
> >  I was told that it was built from a QST article for the 1950's, and most
>of
> >  the
> >  tubes have late 50's date codes on them. If anyone can help me locate the
> >  original construction article and schematic I would be very grateful. 
> TIA,
> >  and 73,
>
>To my knowledge this does not match any design in QST.
>
> >From the tube lineup, it appears to be an adaptation of the HBR concept,
>using miniature tubes and an external supply. Here's my best guess on the
>tube lineup functions:
>
>6AQ5 - Audio Output
>
>12AX7A - 1st Audio
>
>6AL5  Noise limiter & AM detector
>
>6BY6 Product detector
>
>12AU7A BFO
>
>6BE6 2nd converter
>
>6C4 HF oscillator
>
>6BJ6 x2  IF amplifiers
>
>The unknown tube is probably the 1st mixer. What do its innards look like?
>
>Some questions:
>
>How many sections on the tuning capacitor?
>
>What controls are on the front panel, and how are they labeled?
>
>Any crystals in the receiver?
>
>How many coil sets?
>
>Does it have any meters?
>
>What does the dial look like?
>
>--
>
>It IS possible to reverse-engineer a homebrew rx like this. First job is to
>trace out all the wiring - quite a task but very illuminating.
>
>Pix are a big help.
>
>73 de Jim, N2EY
>************************************
>Visit the HBR Receiver Web Site with over 100 pictures of receivers and
>construction notes...... via http://www.qsl.net/k5bcq/
>
>Retrieve reflector archived data via 
>http://mailman.qth.net/mailman/listinfo/hbr

Hi Jim and others that have responded to my request for help. My digital camera
failed about a month ago and I don't have it replaced yet. The tube I can't 
identify
looks like a 6BE6 or something similar to it. The tuning cap has three 
sections and
there are three plug-in coils. I have an s-meter , and the dial is a 
National Velvet type.
Controls number five and are labeled as follows:

RF Gain
Trimmer
AVC-MVC-BFO
BFO pitch
AF Gain
Also I have a switch to turn the ANL on.

There are two additional pots, one on the rear apron and one on top of the 
chassis
near the back. The antenna input is on a three terminal strip and appears 
to be set
up to take both balanced and un-balanced line. The dial is calibrated for 
80, 40, 20,
and 15 meters. The power supply apparently supplied 200 VDC and regulated (?)
105 VDC.

Thanks again, and if I can borrow a camera, Kees has offerd to post them. 
Thanks
again for all of the responses and your help so far. 73,

Kevin, K9HX