[HBR] HBR-67

[Tim Shoppa]

N2EY wrote:
> 1) Use more-common tubes than the compactron and the 7360. (If I had 
> more compactrons and sockets I might think differently)

I don't think there's anything stopping you :-). Compactron certainly drops
the glass bottle count in the converter, and compactrons were certainly
a common theme in the late 60's even early 70's handbooks.

In the '69 handbook, the receiver has a triode/pentode combination 6T9
compactron for the audio output, but there are lots of other choices in 9-pin bottles.
(6HF8).

> 2) Include switchable IF filters for CW/SSB/AM. Small relays could do 
> the job.

There's remarkably little switching in the original, this was pretty
obviously a design goal.

> 6) VFO with more isolation than the 6C4 tickler oscillator used in 
> HB-67. Dual triode with cathode follower? W2YM circuit?
> 9) If a beam-deflection mixer is to be used, make it balanced. If 
> that's too much work, how about a Pullen?

My feeling is that isolation is not particularly needed with beam-
deflection mixers, but that yes going to a dual triode and
making it balanced would be a step in the right direction of
completely eliminating any possibility of pulling, without
increasing the bottle count.

> 15) Audio section designed to deliver 600 ohm headphone-level audio. 
> "Speaker driver" audio stage used if speaker wanted.

The 6T9 shown in the '69 handbook version is certainly capable
of driving a speaker (a big speaker!).

If I had my druthers... I like the HB-65 better. Didn't we discuss
that a year ago? Along with the "Miser's Dream"?

My gut feeling is that the "Miser's Dream" was anything but intended
for the miser, it goes way too far out on all the bells and whistles. The
HB-65 is sweet and simple, and if anything the HB-67 got it even
simpler at some extra cost for the mechanical filter (with a big
plus of reduced complexity).

Tim.