There may be more to it than that. The advantage of sweep tubes was that
they worked very well at lower voltage. For the same power level, the 6146
required more voltage. Also remember this was before the 6146B arrived.

I am not a collector of Drake equipment (and I am not a fan of sweep tubes),
but didn't the TR-3 arrive first? Three tubes were used for a lot of power.
The use of the sweep tubes there may have set the foundation for later
transmitters and transceivers.

I remember a conversation with a friend some 45 years ago. He was lamenting
that the Hallicrafters HT-32 used the 6146, because it was so wimpy and
actually had lower plate dissipation than the 807 it was supposed to
replace. He returned the HT-32 and bought an old Harvey Wells Bandmaster.
Then worked the world on 10 meters with that rig.

73, Colin K7FM

The world AND all TV sets for miles in all directions? That was my friend's
experience... Though it was an interesting shaped radio compared to more common
shapes.

COLIN LAMB wrote:

I remember a conversation with a friend some 45 years ago. He was lamenting
that the Hallicrafters HT-32 used the 6146, because it was so wimpy and
actually had lower plate dissipation than the 807 it was supposed to
replace. He returned the HT-32 and bought an old Harvey Wells Bandmaster.
Then worked the world on 10 meters with that rig.

73, Colin K7FM

COLIN LAMB wrote in message
. net...
There may be more to it than that. The advantage of sweep tubes was that
they worked very well at lower voltage. For the same power level, the
6146
required more voltage. Also remember this was before the 6146B arrived.

I am not a collector of Drake equipment (and I am not a fan of sweep
tubes),
but didn't the TR-3 arrive first? Three tubes were used for a lot of
power.
The use of the sweep tubes there may have set the foundation for later
transmitters and transceivers.

I remember a conversation with a friend some 45 years ago. He was
lamenting
that the Hallicrafters HT-32 used the 6146, because it was so wimpy and
actually had lower plate dissipation than the 807 it was supposed to
replace. He returned the HT-32 and bought an old Harvey Wells Bandmaster.
Then worked the world on 10 meters with that rig.

73, Colin K7FM

Fine Colin... but some of us used the HP-23 Heathkit power supply for the
Drake tranceivers---Heathkit used the 6146 for virtually all of their
transmitters and tranceivers. I myself used the HP-23 for powering my TR-3
with no problems; of course, the jack had to be changed and re-wired. The
HP-23 delivered 700 volts under load---admittedly a bit higher than what
Drake wanted for their sweep tubes; 650 volts.

I think the 6146 pre-dates the Drake rigs. I believe the 6146 came out in
the early 1950's along with the 5763 which supposed to be it's driver (Drake
used the 12BY7A as a driver). I remember the RCA ads for those tubes on the
back of QST.

RG

RadioGuy wrote:

The thought came to me the other day whle thinking about the cost of 6JB6's
nearly $100 for a set; I paid $18.00 for a matched set of three at AES back
in the 1970's and I got plenty of spares. Why did Drake use those cheap ass
sweep tubes in their final instead of the old standard 6146 to begin with?

If you have all that gear in that kind of shape,
$100 invested in the correct tubes seems like a very good idea.

David Stinson wrote:
RadioGuy wrote:

The thought came to me the other day whle thinking about the cost of 6JB6's
nearly $100 for a set; I paid $18.00 for a matched set of three at AES back
in the 1970's and I got plenty of spares. Why did Drake use those cheap ass
sweep tubes in their final instead of the old standard 6146 to begin with?

If you have all that gear in that kind of shape,
$100 invested in the correct tubes seems like a very good idea.

Yes, but his point is that originally they were a few bucks each at the
drug store. These aren't exactly the most robust tubes around, and nobody
today would EVER think of using one in a new design.

Back in the seventies, people were rebuilding old surplus gear to take
sweep tubes because they were so cheap and plentiful. Today people are
rebuilding ham gear built for sweep tubes to take transmitting tubes.
It all goes back again.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."

RadioGuy wrote:
The thought came to me the other day whle thinking about the cost of 6JB6's
nearly $100 for a set; I paid $18.00 for a matched set of three at AES back
in the 1970's and I got plenty of spares. Why did Drake use those cheap ass
sweep tubes in their final instead of the old standard 6146 to begin with?

Because they were just so phenomenally cheap. Sweep tubes were plentiful
and inexpensive and compared with similar power output transmitting tubes
it was hard to justify the cost in a non-ruggedized installation.

Sure, back then it seemed in vogue to use sweep tubes in amateur gear (yea,
sure, Swan gear...) but as I recall, we thought that Drake was kinda cheesy
to use those tubes anyway. I gonna stick my neck out and say Drake
engineering wasn't the end all that the youngsters think nowadays.

It was built to a pricepoint like everything else ever has been. A somewhat
higher pricepoint than the Swan gear, mind you, but it was not built without
design constraints.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

Actually, I think Drake was pretty clever. The tubes cost roughly half as
much as a 6146 and had about the same capabilities. Drake was smart enough
to run them within their ratings, unlike most other manufacturers that used
horizontal output tubes and tried to sqeeze every last watt out of them.
Add to that the fact that (according to tests results in the Bill Orr
Handbook) they actually had less distortion than the 6146 in linear
service, and it looks like a darn good decision.

I still remember a friend of mine running his TR4 full bore on 20 meters
RTTY back in the 1970's. He never had a problem.

73,
Darrell, WA5VGO

Darrell wrote in message
01...
Actually, I think Drake was pretty clever. The tubes cost roughly half as
much as a 6146 and had about the same capabilities. Drake was smart enough
to run them within their ratings, unlike most other manufacturers that
used
horizontal output tubes and tried to sqeeze every last watt out of them.
Add to that the fact that (according to tests results in the Bill Orr
Handbook) they actually had less distortion than the 6146 in linear
service, and it looks like a darn good decision.

I still remember a friend of mine running his TR4 full bore on 20 meters
RTTY back in the 1970's. He never had a problem.

73,
Darrell, WA5VGO

According to my Radio Handbook (Orr) 18th. edition (1970) on page 383:

"To date, the use of inexpensive TV-type sweep tubes as linear amplifers in
amateur SSB gear has been acceptable, regardless of the rather high level of
distortion inherent in these tube types."

I checked the spare parts price list for my TR-4 (January 1, 1977) on the
price of the 6JB6---$4.83. This seems to be in the same price class as the
6146 not to mention that the 6146 tubes were commonly available as surplus
from military or commercial services.

I also operated RTTY with my TR-3 but I had a blower on my tubes.

RG

You miss the point. Drake didn't buy their tubes from the surplus market.
They bought them bulk packaged from the manufacturer. It did make sence
from their standpoint and it didn't compromise the product. From a
boatanchor standpoint I wish they had used 6146's. But when put in their
shoes in 1963, it was a good business decision.

Most horizontal output tubes have distortion products comparable to the
6146 if you keep the voltage and power down to reasonable levels. Third
order products are typically in the -25 Db range which is right in there
with the 6146.

73,
Darrell, WA5VGO




"RadioGuy" wrote in
:


Darrell wrote in message
According to my Radio Handbook (Orr) 18th. edition (1970) on page 383:

"To date, the use of inexpensive TV-type sweep tubes as linear
amplifers in amateur SSB gear has been acceptable, regardless of the
rather high level of distortion inherent in these tube types."

I checked the spare parts price list for my TR-4 (January 1, 1977) on
the price of the 6JB6---$4.83. This seems to be in the same price
class as the 6146 not to mention that the 6146 tubes were commonly
available as surplus from military or commercial services.

I also operated RTTY with my TR-3 but I had a blower on my tubes.

RG

Darrell wrote:

You miss the point. Drake didn't buy their tubes from the surplus market.
They bought them bulk packaged from the manufacturer. It did make sence
from their standpoint and it didn't compromise the product. From a
boatanchor standpoint I wish they had used 6146's. But when put in their
shoes in 1963, it was a good business decision.

Most horizontal output tubes have distortion products comparable to the
6146 if you keep the voltage and power down to reasonable levels. Third
order products are typically in the -25 Db range which is right in there
with the 6146.

73,
Darrell, WA5VGO


Another point of view: If a ham needed new final tubes he could buy
them at any TV shop or parts house, but the 6146 wasn't always available
over the counter without a wait.

--
?

Michael A. Terrell
Central Florida