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eHam Forums => Boat Anchors => Topic started by: KC8DE on March 03, 2012, 09:15:12 PM



Title: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: KC8DE on March 03, 2012, 09:15:12 PM
Just ignore this. Apparently i asked the exact same question 3 years ago.

Doug


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: WN2C on March 04, 2012, 10:02:31 AM
So did you find the answer? Maybe it should be posted so that those that are new to the hobby will know!

73 de rick wn2c


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: K4RDH on March 24, 2012, 08:42:21 PM
The difference is that the 6146, 46A & 46W have a 25W plate dissipation rating and the 6146B has a 35W dissipation rating.
As long as the design has them working in the mid-range there will be no problem.  Newer rigs, such as Kenwood hybrid like the TS-830S, designed in the 70's & 80's shouldn't have any problems.  Older rigs, say pre-60's, that depended on the 46B rating of 35W and worked them at the edges of the operation range might very well have problems.


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: N3QE on March 25, 2012, 07:26:48 AM
Older rigs, say pre-60's, that depended on the 46B rating of 35W and worked them at the edges of the operation range might very well have problems.

??? 6146B was introduced in 1964. Hard for a pre-1960 rig to have specced them from the get-go.


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: K0OD on March 25, 2012, 09:53:20 AM
Timely question for me. The 30-year old 6146B's in my 1977 TS-820 were only putting out about 50 watts so I just replaced them with NOS JAN 6146W ($25 each). Also replaced the 12AU7 driver with a NOS one. Now max output is about 85 watts on CW with 800v on plates. But many Kenwood hybrid restorers report 100-120 watts output on the lower bands. 

6146B's cost more than 6146W's from many sources. I'm inclined to think I should have gone with 6146B's. But the restored and repainted 820 is virtually never used. It does look MAHVELOUS!


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: W8JX on March 25, 2012, 10:38:14 AM
Timely question for me. The 30-year old 6146B's in my 1977 TS-820 were only putting out about 50 watts so I just replaced them with NOS JAN 6146W ($25 each). Also replaced the 12AU7 driver with a NOS one. Now max output is about 85 watts on CW with 800v on plates. But many Kenwood hybrid restorers report 100-120 watts output on the lower bands. 

6146B's cost more than 6146W's from many sources. I'm inclined to think I should have gone with 6146B's. But the restored and repainted 820 is virtually never used. It does look MAHVELOUS!

My 830 gold label that I got new around 89 as I recall still has original driver and finals. It will make a little over 120 watts on 40 still. When new it would do 135 watts.


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: W5RKL on March 25, 2012, 04:25:12 PM
The  driver tube in the Kenwood hybrids (520, 530, 820 and 830) is a 12BY7/12BY7A not a 12AU7.

Many Kenwood hybrid owners seem to think it's necessary to change the driver tube when the final tubes are changed.

If the drive adjustment (Peak DRIVE control in TUNE) produces a strong and stable ALC indication during tune up then there's no need to replace the driver tube when changing final tubes.

73s
Mike


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: K0OD on March 25, 2012, 05:50:52 PM
Yeah it was a 12BY7A. The 30 year old one was possibly good but the NOS replacement only cost $10 to add to my order.

Besides, the new tube came in a mint condition GE box that bore the mottos "Progress is Our Most Important Product" and "MADE IN U.S.A."

Ronald Reagan GE spot... [roll the patriotism] :
http://www.youtube.com/watch?v=xeSmNaKCjaw


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: KD0REQ on March 26, 2012, 01:44:20 PM
there is no "official" answer and lurking on the boards, I have seen a lot made out of dicey Motorola and Collins final cages over this.

if your set has enough adjustment in the neutralization network and they didn't put the cheapest possible parts in there that would not arc over during pre-ship conditioning, the 6146W/B tubes should work.  if they neutralize, it's fine.  most rigs have enough leeway in the design for all sorts of diversions from "perfect" that they should work.

if they're "all over the map" when you try to neutralize, then the final cage was engineered to the half-penny exactly what was needed, and you need the older tubes.

you're a ham.  try 'em.  put 'em back on eBay if you can't use 'em.


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: N3QE on March 27, 2012, 12:13:27 PM
The  driver tube in the Kenwood hybrids (520, 530, 820 and 830) is a 12BY7/12BY7A not a 12AU7.

Many Kenwood hybrid owners seem to think it's necessary to change the driver tube when the final tubes are changed.

Heath HW-100/SB-100 series radios used a 6CL6 for the driver of the 6146B. In my experience the driver needs replacement more often than the finals. (Averaging over past 30 years of ownership!).

Tim.


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: K4RDH on March 27, 2012, 03:48:50 PM
Older rigs, say pre-60's, that depended on the 46B rating of 35W and worked them at the edges of the operation range might very well have problems.

??? 6146B was introduced in 1964. Hard for a pre-1960 rig to have specced them from the get-go.

My bad, I hit the 6 key instead of the 7.  Should have read pre-1970 rigs.  ::)


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: KM1H on April 14, 2012, 12:52:33 PM
Ive rewired the sockets in my TS-830's and use the 12V 6146B varieties, 8552, 6883B, 8032A. A lot cheaper so far.

Carl


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: W8JX on April 14, 2012, 03:05:42 PM
My 830 still has original finals and still makes well over 100 watts out. Given how long they last, I would not worry much about price of them. I have run idle bias current a lot lower than factor specs for nearly as long as I have had it (23 year) which lowers zero signal thermal load on tubes and they run a bit cooler.


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: W9GB on April 15, 2012, 10:36:32 AM
Quote
Ive rewired the sockets in my TS-830's and use the 12V 6146B varieties, 8552, 6883B, 8032A. A lot cheaper so far.
Always loved that tube.  Never built a radio using it, on the bucket list.


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: N6PJB on April 20, 2012, 03:11:32 PM
RF Parts states that the GE 6146W is NOT interchangeable with 6146B. Not recommended for Kenwoods.

I use the Sylvania-ECG/Phillips 6146W for my Kenwood 820S with about 125 watts output. My original 6146Bs tubes became backups when they starting putting out 100 watts last year.


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: G3RZP on April 20, 2012, 03:15:36 PM
If nothing else, the heater current for the 6146W is different  (1.25A) to the current for the 6146B (1.125A)


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: KE4DRN on April 23, 2012, 07:57:14 PM
hi

Don't pay more for matched pair, the kenwood hybrids do not require them.

added: the kenwoods use 6146 in parallel not push pull operation.

http://www.nj7p.info/Common/Tube/SQL/Tube_query.php?Type=6146w

http://www.nj7p.info/Common/Tube/SQL/Tube_query.php?Type=6146b

73 james


Title: RE: Age old question: Replacement finals for TS-830S - (JAN) GE 6146W OK?
Post by: G3RZP on April 24, 2012, 02:56:48 AM
Over the years 1970 to 1975, I designed and put into commercial production various transmitters that in total, used around 8,000 6146B tubes - some in 2 tube PAs, some in 3 tube PAs. I also measured the performance of a number of tubes (13) from 3 different new batches. For given bias, screen and plate voltages, the plate currents ranged from 4 mA to 28mA. The average was 13mA with a standard deviation of 6mA.

Not as bad as 6JS6s, but setting up for 50mA total plate current for a pair, one could be running about 44mA and the other one 6mA.

Even tubes from the same batch showed a 2:1 spread.

Now because of the relatively intermittent  use - not many people transmit for hours on end - you can get away with it. In an extreme case, you can see the anode inside glowing. But personally, I don't like it, and prefer either matched tubes or a separate bias pot for each tube.