[HBR] Another project?

[Walt Hutchens]

I actually have a sort-of HBR waiting for attention.  A year or two back
I bought a G3RKK homebrew receiver that needs its metalwork and wiring 
redone.

Like the G2DAF sets, the G3RKK design was published in the RSGB bulletin
and in the 3rd edition of the RSGB Radio Handbook.  It is said to have 
been constructed in considerable numbers.  I had never heard of it until 
I bought this example.

The G3RKK is similar to the W6TC designs in being double conversion
using fixed IFs of 1620 and 85 kcs.  The big difference is the use of a
bandswitching front end instead of plug in coils.   BUT the front end
assembly (separate subchassis about 7" x 7") was available as a
pre-wired assembly from Electroniques -- a UK company.

Buildability-wise this is not quite the equal of the HBRs -- there are
several shields under the chassis and other non-trivial work -- but the 
use of a prewired front end with no coils to wind probably made it even 
easier for some builders.

I suspect that both stability and performance were somewhat below the
HBR-series sets.  The coils are necessarily much smaller -- maybe 3/8" 
diameter? -- meaning lower Q.  They're on nylon forms -- excuse me, 
*formers.*  Drift could be better or worse than the HBRs, but probably 
not greatly better, in fact the Radio Handbook says there was a later 
version that (among other things) reduced the drift on the higher bands.

(The improved version is said to have been described in an issue of the 
RSGB Bulletin; I wonder if anyone has a lead to that article?)

The circuitry is 'very conventional' -- diode detector for AM, dual 
triode product detector for SSB, single ended audio, no Q-multiplier in 
the front end.

Except for the factory-built front end assembly which is in decent 
shape, the metalwork and wiring on my example are poor.  But all the 
critical parts are there, including a pre-calibrated Eddystone dial (I 
expect the printed dial scale came with the front end chassis), that 
bandswitching front end, the tuning cap and the IFTs.  So it could be 
turned into a kit with no more trouble than you'd expect.

With the current eBay HBR-16 standing at $350 with several hours to go, 
I suspect it won't be coming here, so that's one chunk of time that'll 
be free.

Gee ... a $350 reserve.  But the marketplace says that's realistic.  I
wonder what the guy's actual bid was?  $400?  $500?

Walt
KJ4KV