[HBR] HB-65, anyone, anyone?

[N2EY at aol.com]

In a message dated 12/2/06 11:06:28 AM Eastern Standard Time, 
shoppa_hbr at trailing-edge.com writes:


> N2EY at aol.com wrote:
> > I don't think it tunes 10 meters

DOH! 

I meant "11 meters". And it doesn't - the three xtals are for 10 meters, 
tuned in three 600 kc. chunks.


 as designed, though. Check the het xtals - 
> 
> > it doesn't have one for below 28 Mc.
> 
> At least in the '66 handbook, it has a bunch of crystals in the 10M/11M
> range.
> 

The basic receiver tunes a 600 kc slice, so it takes three xtals to cover 10 
meters. Hams lost 11 meters in 1958, and there was no reason to include 11 
meter coverage in a 1965 rx.


> > The design of the HB-65 was obviously influenced by the "Miser's Dream" 
> which 
> > was in QST about the same time, and by the W6TC HBRs. 
> 
> > > Looks to me a lot like DeMaw's solid state receivers of the 70's.
> >
> > How? 
> >
> > The HB-65 uses only LC filtering - no xtal or mechanical filters. Multiple 
> 
> > conversions, too. 
> 
> I was thinking of the crystal controlled-converter in front of the
> "tunable IF" (aka 80 and 40 meters.)
> 

That's a very old idea. My 1949 Handbook has converters for 20, 15 and 10, 
intended to go in front of an 80 meter rx. 

If you want to see a complete rx, W2LYH's receiver, in QST about 1961, tunes 
3 to 4 Mc and is preceded by a crystal controlled converter. He built that rx 
to replace the converter-and-BC-342-N setup he had been using.

Look at the HBR website for pictures of my "silver receiver" from about 1973. 
The rx shown there is for 80 meters only. It was used with a converter for 40 
and 20. 


> > > Very well-balanced radio, not too much gain, no whiz-bang features,
> > > well thought-out bandswitching that doesn't try to give the kitchen
> > > sink but instead gives exactly what is needed in a ham receiver.
> 
> > Sort of.
> >
> > For all that complexity, there's no sharp filter for CW. The AGC is audio 
> > derived and the selectivity is so far from the antenna on 20 through 10 
> that the 
> > dynamic range is probably compromised. Some unusual tubes, too. Uses a lot 
> of 
> > IF transformers that are difficult to get today (two 1700 kc, four 100 kc, 
> 
> > plus 100 kc. BFO). Even though it has AGC there's no S meter.
> 
> Again, I call most of the missing features bells and whistles :-). The
> bunch of IF transformers is common to all the double-conversion non-crystal-
> filter receivers.
> 

That doesn't mean they're a good idea if something better is available for 
the same $. 



> > The ARRL Handbook projects come from three sources:
> >
> > 1) Projects that were originally QST articles written by the ARRL Hq 
> staff. 
> > 2) Projects that were originally QST articles written by hams not on the 
> ARRL 
> > Hq staff.  
> > 3) Projects that were developed by the ARRL Hq staff specifically for the 
> > Handbook.
> >
> > How much of each type appeared in the Handbook varied over time. My 
> > impression of the '65 and '67 Handbooks (I don't have a '66) is that most 
> of the 
> > projects in them are from the 3) category, above. The HB-65 is definitely 
> 3).
> >
> >
> > >Was it (by my guess) Doug DeMaw?
> >
> > It's almost certainly a W1DX (By Goodman) design and construction project. 
> 
> 
> Hmm, could be. Although DeMaw's trademark to me was always simplicity
> in bandswitching and purposeful exclusion of the kitchen sink features,
> if you look at his earliest articles he had not quite perfected the
> formula, so I was allowing a little leeway :-). Certainly the Goodman
> and Hayward designs tend in that direction too.
> 

None of the Handbook receivers of that era are very complicated. 

> I remember a lot of late 60's/early 70's construction articles
> that specifically identify the Kurz-Kasch knobs used. Were those
> DeMaw's or somebody elses? Somebody really liked those knobs, and
> somebody really liked those 7360's!
> 

They probably had a box of them...

Remember too that the mindset of the builder 40+ years ago was probably very 
different from today. Most ARRL Hq articles from that time, particularly in 
the Handbook, were based on the use of new parts by well-known manufacturers, 
available at large radio stores or by mail order. Some surplus and old-TV stuff 
did show up in W1ICP's projects, but the HB-65 wasn't one of them.

W6TC's HBRs (except, possibly, for the HBR-14) were in that same mold. One of 
his design goals was that a ham could order every single part needed for an 
HBR out of the better-known catalogs. Of course the ham with a junkbox or 
suitable surplus could substitute and save money, but that wasn't a primary goal.

Today we often have to design around what we have, or can get.

As for the 7360, it wasn't rare or pricey in its time. If you were buying all 
new parts, it could actually save you money by reducing the tube/parts count. 
And it's a pretty good receiving mixer. 


> > The HB-65 has some good ideas but it could be a lot better.
> >
> > Here's how I'd build that sort of rx:
> >
> > First off, if a source of good 1700 kc xtals can be found, build crystal 
> > filters for 1700 and eliminate the conversion to 100 kc and all the hard 
> to get 
> > IFTs. Perhaps a variable bandwidth ladder filter as used in the Elecraft 
> rigs? 
> > Or perhaps package the filters as subassemblies, with one for CW and one 
> for 
> > SSB, or even more.
> >
> > Moving the selectivity closer to the antenna will improve the dynamic 
> range, 
> > and simplify the rx. 
> >
> > Next, I don't know if I'd use a 7360 as shown, or in a balanced circuit. 
> > Maybe try a different beam-deflection tube like the 6JH8 or 6ME8, or maybe 
> a 
> > Pullen or other triode mixer. In fact a receiver like that might be a good 
> test-bed 
> > for different mixers.
> 
> This was still in the every-construction-project-must-use-a-7360 phase,
> I think! Yes, you're right, it isn't automagically the only mixer possible.
> 

It's certainly better than, say, a pentagrid.

> I think I once found a handbook SSB transmitter that used not one, 
> not two, but three 7360 tubes!
> 

Probably as balanced mixers and the balanced modulator. Try building the same 
rig with other tubes and see how high the tube count goes.


> > I'd build the VFO as a unit, rather than on the chassis, and I'd include 
> some 
> > kind of buffering/isolation. Maybe an ARC-5 tx capacitor with built-in 
> dial 
> > drive. Since the VFO tunes just one range, why not unitize it?
> >
> > The dual diode product detector could probably be replaced by an active 
> > tube-type detector that would have some gain, easing the requirements for 
> audio 
> > gain. I'd use a bigger chassis in order to have more room and a bigger 
> panel. A 
> > balanced mixer in the converter (maybe a beam-deflection tube?) to 
> eliminate IF 
> > feedthrough problems mentioned in the article. 
> >
> > An interesting feature of the design is that it covers the WARC bands 
> as-is, 
> > with a little creative use of the preselector tuning and the bands tuning 
> > backwards.
> >
> > To receive 30 meters, (I'm assuming the converter tuned circuits will tune 
> 
> > down to 10 Mc., or can be modified to do so),  select the 15 meter xtal 
> (14.0 
> > Mc.) and peak the 7360 grid circuit for 80 meter reception. 10.1 will show 
> up at 
> > 3.9 Mc. on the dial and 10.15 will show up at 3.85. WWV at 10.0 can be 
> tuned 
> > in at 4.0 on the dial.
> >
> > To receive 17 meters, select the top-end-of-10-meters xtal (22.0 Mc.) and 
> > peak the 7360 grid circuit for 80 meter reception. 18.068 will show up at 
> 3.932 
> > Mc. on the dial and 18.168 will show up at 3.832. 
> >
> > To receive 12 meters, select the bottom-end-of-10-meters xtal (21.1 Mc.) 
> and 
> > peak the 7360 grid circuit for 80 meter reception. 24.890 will show up at 
> > 3.790 Mc. on the dial and 24.990 will show up at 3.890.
> >
> > Of course one could add xtals and get the WARC bands to line up nicely, 
> but 
> > that means more quartz and extra coils.
> 
> Wow, that's a lot of bells and whistles :-). 

How so?

To tune the other bands, you have to do the same rigamarole:

To receive 20 meters, select the 20 meter xtal (10.4 Mc.) and peak the 7360 
grid circuit for 80 meter reception. 14.0 will show up at 3.6 Mc. on the dial 
and 14.35
will show up at 3.95.

To receive 15 meters, select the 15 meter xtal (14.0 Mc.) and peak the 7360 
grid circuit for 40 meter reception. 21.0 will show up at 7.0 Mc. on the dial 
and 21.45
will show up at 3.95.

To receive 10 meters, select one of the 10 meter xtals and peak the 7360 grid 
circuit for 40 meter reception. 10 meters tunes in three parts.

Of course in all cases the converter grid circuit has to be peaked to the 
band in question.

Simplicity in band switching is repaid in complexity of operation.

You are right, in that
> 
> as published the HB-65 design is less modular and less step-by-step
> than many of the HBR's.


It has some nice features such as having a one-range VFO and bandswitching. 
It's also pretty compact and uses a solidstate supply. I suppose that with a 
bit of work and a bigger panel, the 898 dial could be fitted. 

I wonder what the total parts cost was, back then, compared to an HBR-16? The 
xtals cost a bit, but you didn't need all those coil forms and APC trimmers. 

73 de Jim, N2EY