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

Mike Silva wrote in message
ups.com...
FWIW, I just looked in a 1970 Newark catalog. 6146As were about $4,
and 6146Bs about $5. Smaller sweep tubes went around $3 and larger
ones around $4.

Excellent... thank you for looking up the sales price of the 6146 and sweep
tubes.

RG

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

If things get really tough, try what I've done. I have some 12JB6's and
some 18JB6's. The final filaments can be re-directed and run via an
external xformer. It works fine. However, I just bit the bullet and
bought several pairs from reasonable sources. Given the number of hours
I use the Drake C-line each month or year, I'm sure I'll be OK until I
"check out of the net".....

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

Noone has raised the issue of how long 6JB6s last.

If they are used with caution they last for a long time, but if one =
tries to squeeze the last watt out of them (and the 6JB6s invite you to =
do so, thanks to their strong cathode emission) they can last for a VERY =
short time.

The 6146 have a lower cathode emission and do not then lend themsleves =
to be squeezed so badly as the 6JB6s. So there is less harm to =
inadvertently destroy them.

To my experience the Sylvania 6JB6s (those sold by Drake as spares) =
perform better than the GE 6JB6s, and are are easier to neutralize. The =
RCA 6JB6s, luckily much less common, were no good.

73

Tony, I0JX

------------------------------------------------------
Antonio Vernucci, I0JX US call: K0JX
50-MHz beacon: 50.004 KHz FSK 10W 5/8 vertical antenna
home page: http://www.qsl.net/i0jx
e-mail: k0jx {at} amsat {dot} org
------------------------------------------------------
"RadioGuy" ha scritto nel messaggio =
...
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?
=20
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.
=20
(Yes... I have a complete Drake station (including amplifier)---the =
whole
line-up in pristine, vitrually unused condition in crisp factory =
cartons
including accessories, catalogs and a handful of the right-angle =
Switchcraft
microphone (black cap) and key (red cap) plugs that Drake originally
supplied not that PL-whatever. Original owner---me---so it's not sour
grapes.)
=20
RG
=20

Antonio Vernucci wrote in message
...
I don't recall the 6146 was that expensive. We could find them at the
hamfest, surplus and they were routinely given away from one ham to
another... heck,

What you say is true for a ham in need of just replacing a pair of tubes.
But it would not have been true at all for Drake.

A company producing ham gear cannot depend on tubes found at a good price
here and there. They have to place a contract with a tube manufacturer who
can guarantee delivery in time and in the required quantities. Prices are
then market prices, not surplus prices.

73

Antonio I0JX

Well, the tube (6146) was in constant production during Drakes operation
(about 30 years) so it would imply that they were very common and
cheap---practically every other amateur equipment manufacturer was using the
6146. Large numbers were used by the military and commercial services. My
gosh... if Heath was using them they certaintly couldn't have been that
prohibitive to design with. So it begs the question why Drake was using
them.

RG

Michael A. Terrell wrote in message
...
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

Well... maybe if you were using a single tube that would be the case. The
Drake gear (besides gear from other manufacturers) used more than one tube
requiring them to be matched. I recall Drake sold matched sets of tubes
after checking their cathode currents in a test fixture. The tubes were
them marked and collected into sets for sale. I recall seeing the number
'18' on the envelope of a matched set of 6JB6's. What '18' meant I just
don't know. I also recall some folks back then claim the the tubes were
also matched on the basis of plate capacitance. I'd look at the matched
sets that I have but they have been in sealed packages for nearly 30 years
so I hate to open them.

The 6146's weren't a problem... we always seemed to get them if we needed
them---they seemed to be everywhere. They were sort of like antenna
insulators---if you needed them someone had them and would give them to you.
I never bought a 6146... One fellow gave me a couple of boxes of 6146W's
(yea... they were in the white boxe with the black print on the side ;-). A
lot of manufacturers were using the 6146's in their designs and the tubes
had been around a long time---for decades.

RG