The AM Forum

On a recent AWA net the discussion was about the Harvey Wells Bandmaster rigs of the late 40's. I have a 50C Senior and it is pretty much stock with the modulator and carbon mic input. (2) 6AQ5's, 807, 6L6 (1614) modulators.

Another ham in our group has a model that is marked a 'D' model. It also has the base VFO BUT it has no speech amplifier internally. In addition instead of the (2) 6AQ5's it has a 6AK5 driving a 6CL6 and 6550's as modulators. The owner says it appears factory. Was there ever a unit that left the factory with this tube lineup? This really sounds like an alien unit. I can understand someone plugging in 6550's in place of the 6L6's, although I would not think that necessary BUT the 6CL6 is a 9 pin vs the 6AQ5 7 pin so someone would have to have changed sockets and wiring. Has anyone seen anything like this? Any info on this would be appreciated.

http://www.swedeart.com/harvey/index.html

Above is a site dedicated to Clifford Harvey, W1RF and his various companies.

I recall reading one remembrance that after one of the floods in the late fifties, Clifford gave away or sold at minimal price stock that had gotten wet, cases in particular, to the local hams.  

It's possible that different innards could be in a mismatched case.  Or someone may have removed the "D" mic preamp.  I have two D's and they have variations in specific components and exact layout.  One has holes for the VFO mounting, the other does not.  It is obvious that Harvey-Wells took advantage of bargain component sources.  I can't account for the tube variation.  

bill

Don't know the answer, but Doug I was curious if your 50C has the oscillator
tube cathode grounded? I also have a 50C senior and it grounded, looks factory, but the
schematics I have,show it keyed along with final, maybe that was other/later model..
Problem of course is with B+ on you hear the oscillator through the rx so have to key B+ first,
but it does have nice note that way...

73, Chuck

Since the 6550 didnt come out to 54 and H-W was definitely low end components Id vote for a Frankenradio.

OTOH if that guy wants to sell a pair of good USA 6550's at no audiophool prices, Im looking as the ones in my CE-100V are getting tired.

I had a D model mobile and portable around 56-59 on 75, 20 and 10 AM and some 40-20 CW.

Carl

That was going to be my next question - when did the 6550's first appear on the market. So you answered that. If the owner takes some detailed photos I will pass them along

I buttoned my 50C back up and put it back on the shelf and moved on to other projects. If I get it down again I will check the keying circuit.

Another question about these old rigs that used cloth covered rubber wiring. Most of it is brittle and you can hear and feel it crack when you move it. I wonder if there is some miracle concoction that you could saturate the wire with to rejuvenate the rubber? I kind of doubt it and replacement may be the only answer on some of these old rigs. 

Doug

Replace the wire.