[HBR] Present day HBR

[W6ph at aol.com]

In a message dated 1/9/2011 9:01:43 AM Pacific Standard Time, 
hbr-request at mailman.qth.net writes:

I'm assuming the goals of 'you can build it' and 'it will outperform 
most commercial sets of equivalent technology' would stay the same. I 
think that would mean keeping the plug in coils. 

Beyond that, however, things are less certain. 

Thoughts, anyone? 

Walt Hutchens 
KJ4KV 

A good question.  Considering the lack of parts availability, there would 
be significant changes.
Ted liked the idea of plug-in coils for simplicity as well as better 
performance.  Today he might
settle for a single band design with permanent coils and individual 
converters for other bands
of interest.  I don't think he would change his philosophy of aversion to 
bandswitching.  He may 
have gravitated to a single conversion design with crystal filters at an IF 
of 1600 KHz (or some 
other frequency) similar to the Heathkit SB series.  He wouldn't have the 
closeness to an 
industrial supplier that he had with the old JW Miller company.  That 
kinship was one of the 
reasons that the HBR was so successful.
 
Today it is still possible to build a similar receiver with a few 
mechanical and electrical
compromises without straying from the original design.  IF transformers and 
BFO 
transformers for 85 KHz and 1415 KHz are ubiquitous from the thousands of 
WW II 
command sets.   FM receiver tuning capacitors are available or the tuning 
capacitors 
from the command sets could be used with some modification.  He may have 
opted
for a dual section variable (for first mixer and first LO) and used another 
variable
capacitor to peak the RF section, preselector style.  Vacuum tubes are 
still readily 
available.  The HBR that we build today may not look as pretty but would 
function 
well and give the builder the pride of his own workmanship.
 
When reading his notes in "Recollections of a Receiver", it is obvious that 
Ted wanted 
to stay away from the edges of performance to give room for the average 
TD&H to be 
successful in building this receiver.  His design still trumps any of the 
postwar 
commercial receiver designs that were affordable. 
 
For the benefit of newcomers to this forum, there are two excellent 
resources of 
information for anyone contemplating construction of an HBR.  First is the 
HBR
website hosted by K5BCQ.  The other is the "Recollections of a Receiver" CD
by Jay Helms, W6HHT.  Both resources have information that was never printed
in QST.
                                        73, Kurt, W6PH