The last of the tube TR4's had 1 khz readout.....and a WHOLE lot more
repeatable, and end to end accurate then the SB102!!

....Dave

wrote in message
oups.com...
On Jul 8, 8:29 pm, Doug wrote:


What do you mean by "What a thing to consider"???

I mean, "BEST Tube-Type Transceiver" is a strange and difficult
consideration. It's the topic of this thread.

The problem with Heathkit's SB transceivers isn't the soldering.
That's an old-ham's saw. It's not quite up there with the "Acid Core"
urban legend, but it's close.

While I have encountered poor solder jobs, I have only seen one
problem that was clearly solder based and that was in a factory,
machine-made part.

The problem with Heath are the mechanicals. The design is clever;
the parts are mediocre; the mechanical build quality is generally
horrible.

A case in point is the LMO pinch drive and the tension on the rings.
I've spent hours cleaning and adjusting the drive and when it's right,
it's terrific. It's light, smooth, precise, no backlash. I have a
Heath SB tuning knob with lead weights in it. It's a perfect match
for the LMO drive.

Even when you have the pinch drive adjusted right, the 100 kHz
indicator is off. That's a 30 minute trial and error adjustment where
1/64 inch position shift of a piece of metal under a machine screw is
amplified by an articulated arm. After the fine tuning, you're
fighting the play in stamped parts.

Then there's the fiduciary on the LMO. What's with that?

Every fiduciary knob is corroded. I polished one until it shines.
It's still a knob on a 1/8 inch shaft in a hole drilled in plastic, no
fore-aft stop, driving a piece of wobbly plastic with friction.

Another problem with Heath are the thin skirts on the knobs. The
skirts could be thicker and more precise. When I put the knobs back
on a Heath, I use a feeler gauge to space the skirt from the front
panel. That's after I find the low spot on the skirt.

The bezel on the SB's should be more like Collins. That was a bad
place for Heath to cut corners. A thick solid bezel would give the
fiduciary's drive shaft more bearing surface.

How did they get the bezels on the DX-60 and the HW-16 so right and
the SB so wrong?

The phenolic circuit boards are mediocre. The design is fine. Thick
FR4 glass epoxy would have made the Heath's much better.

On sheer performance, the Heath's are up there. Hot receivers, 6 pole
crystal filters, stable, 1 kHz readout, etc. Drake and Halli didn't do
that until they went digital.

-C

Years ago there was a guy that was making a "solid state tube". for
sweep tube replacement. It consisted of two or three transistors an a
potted cast assembly on an octal base, very much like solid state
rectifier tube replacements. A customer claimed he'd busted one apart
and it looked like a horizontal output transistor on a plate, some
small transistors, a resistor and was put in black hard potting
compound with some smppth small rocks for packing. He was not
sufficiently on the ball to have made a schematic.

Failing that, converting the beasts to a transmitting tube of some
sort seems the only way to go,as sweep tubes are a thing of the past.
Apparently they take a lot of different internals from audio types,
which are the market today.

wrote:

Failing that, converting the beasts to a transmitting tube of some
sort seems the only way to go,as sweep tubes are a thing of the past.
Apparently they take a lot of different internals from audio types,
which are the market today.

Yes, I grew up watching folks changing old surplus military gear to
take cheap commercial sweep tubes. Now I am watching people converting
cheap commercial gear to take surplus military sweep tubes....
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Scott Dorsey wrote:

wrote:

Failing that, converting the beasts to a transmitting tube of some
sort seems the only way to go,as sweep tubes are a thing of the past.
Apparently they take a lot of different internals from audio types,
which are the market today.


Yes, I grew up watching folks changing old surplus military gear to
take cheap commercial sweep tubes. Now I am watching people converting
cheap commercial gear to take surplus military sweep tubes....
--scott

I converted my old Hallicrafters SR150 from sweep tubes (6DQ6's if I recall)
to 6146s. It is still around the local ham community and running fine. The
nice things about the 6146's was that they are small enough to fit in almost
any PA subchassis, and all I had to do was rewire the sockets.

Sure wish I still had it. I let it go about 25 years ago!

Irv VE6BP

Irv Finkleman wrote:
Scott Dorsey wrote:

reseauplate wrote:

Failing that, converting the beasts to a transmitting tube of some
sort seems the only way to go,as sweep tubes are a thing of the past.
Apparently they take a lot of different internals from audio types,
which are the market today.


Yes, I grew up watching folks changing old surplus military gear to
take cheap commercial sweep tubes. Now I am watching people converting
cheap commercial gear to take surplus military sweep tubes....
--scott

I converted my old Hallicrafters SR150 from sweep tubes (6DQ6's if I
recall)
to 6146s. It is still around the local ham community and running fine.
The
nice things about the 6146's was that they are small enough to fit in
almost
any PA subchassis, and all I had to do was rewire the sockets.

Sure wish I still had it. I let it go about 25 years ago!

Irv VE6BP

TV sweep tubes don't like to be run linear. I recall seeing a 16 x 6LQ6
amplifier in the Handbook (or was it QST?) eons ago. I shudder at the
thought of the IMD3 response! 6146s are a bit better than sweep tubes. My
favorite tube in terms of linearity would be the 807/1625, albeit a bit
taller than the others.

I still have my first SSB xcvr, a new-to-me SB102. I would concur with most
of what others have said about the cheesy mechanicals. Even with fresh
tubes in the frontend & IF and aligned, the receiver seemed to fall off in
sensitivity above 20m. 3 elements on 15m at 38' made up for it. I added a
Fox-Tango Club 500Hz CW filter before retiring it.

73,
Bryan WA7PRC

Bryan wrote:

Irv Finkleman wrote:
Scott Dorsey wrote:

reseauplate wrote:

Failing that, converting the beasts to a transmitting tube of some
sort seems the only way to go,as sweep tubes are a thing of the past.
Apparently they take a lot of different internals from audio types,
which are the market today.


Yes, I grew up watching folks changing old surplus military gear to
take cheap commercial sweep tubes. Now I am watching people converting
cheap commercial gear to take surplus military sweep tubes....
--scott

I converted my old Hallicrafters SR150 from sweep tubes (6DQ6's if I
recall)
to 6146s. It is still around the local ham community and running fine.
The
nice things about the 6146's was that they are small enough to fit in
almost
any PA subchassis, and all I had to do was rewire the sockets.

Sure wish I still had it. I let it go about 25 years ago!

Irv VE6BP

TV sweep tubes don't like to be run linear. I recall seeing a 16 x 6LQ6
amplifier in the Handbook (or was it QST?) eons ago. I shudder at the
thought of the IMD3 response! 6146s are a bit better than sweep tubes. My
favorite tube in terms of linearity would be the 807/1625, albeit a bit
taller than the others.


I rebuilt an RCA TTU-25B 25 KW UHF TV transmitter about 18 years
ago. It had 17 6146 tubes in the video modulator. What a pain in the
ass to match 16 6146 tubes for the output stage.


--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

On Jul 10, 6:36 pm, "Dave Edwards" wrote:
The last of the tube TR4's had 1 khz readout.....and a WHOLE lot more
repeatable, and end to end accurate then the SB102!!

...Dave

Yes. Good point.

I don't own Drake except for a 2B/2BQ that's been in storage for 35
years. Don't know a lot about them, never operated a TR.

Overall though, the SB-102 package, as part of the Heath SB system
which includes several amps, scopes, etc., was the premier 1960s/1970s
set up. The weakness of the SB's was the mechanical build quality
and the mechanical alignment.

Drake PTO vs. Heath LMO is an interesting comparison. My SB-102 is
not seen bench time yet but I've had an SB-303 (same solid state LMO
albeit without the tubes nearby) on a frequency counter for a week.
The drift measured in the few tens of Hz! This was in an un-
airconditioned room.

Well, if you ever get the opportunity....get a nice TR4C!
I have an SB303, 301 and an SB102. They are mint 'keepers', but they are
just light years away from the overall quality and performance of the TR4's
....Dave
wrote in message
ps.com...
On Jul 10, 6:36 pm, "Dave Edwards" wrote:
The last of the tube TR4's had 1 khz readout.....and a WHOLE lot more
repeatable, and end to end accurate then the SB102!!

...Dave

Yes. Good point.

I don't own Drake except for a 2B/2BQ that's been in storage for 35
years. Don't know a lot about them, never operated a TR.

Overall though, the SB-102 package, as part of the Heath SB system
which includes several amps, scopes, etc., was the premier 1960s/1970s
set up. The weakness of the SB's was the mechanical build quality
and the mechanical alignment.

Drake PTO vs. Heath LMO is an interesting comparison. My SB-102 is
not seen bench time yet but I've had an SB-303 (same solid state LMO
albeit without the tubes nearby) on a frequency counter for a week.
The drift measured in the few tens of Hz! This was in an un-
airconditioned room.