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 Post subject: Re: 6l6GC Replacement tubes for Heathkit IP-17
PostPosted: Feb Wed 13, 2019 2:40 pm 
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NW2K wrote:
Don Cavey wrote:
I know that this is straying a bit off topic but my understanding is that the 6BG6GA is approximately the he same as a 6L6GC.


Regarding plate dissipation, the RCA and GE datasheets for the 6BG6-GA give 20w. 6L6GC is 30w.
So, closer to the 6L6GB/5881 then I guess. Oh well. I didn't have the RC-30 handy. Thanks for pointing that out.

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 Post subject: Re: 6l6GC Replacement tubes for Heathkit IP-17
PostPosted: Feb Wed 13, 2019 4:54 pm 
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Location: Tustin,CA
Hello,
FWIW, if you own a Heath PS-4, IP-32, or an IP-17 and its variants, you need to use 6L6GC 30W tubes to meet their specification. There is about 600V on the plates of the 6L6GCs. At low voltage and 100 mA continuous, that's 60W of plate dissipation, and these supplies are spec'd to 0-400V. Also, don't forget that they are also spec'd at 125 mA intermittent. Sure, you can plug the 6L6, 6L6G, 6L6GB, etc., into those sockets, and I have seen plenty of supplies that have done exactly that on eBay, but you would need some kind of de-rating chart to use the supply within the limits of those tubes. Do those 6L6GCs need to be matched?? IMO, they do. Every PS-4 thru IP-17 variant I have sold has had matched tubes in them. I used matched 1 ohm 1% 1W metal-oxide resistors in the cathodes of each tube to verify matching. The last IP-32 I rebuilt came with a pair of Hitachi 6L6GCs that were only matched 30%/70% and their discolored silkscreen on one tube told the tale. I don't always use these supplies to their max specs, but I DO on occasion, and I know the tubes will handle the workload. These are very good supplies with the right tubes and a fresh set of filter caps, and I have a 40 year history with them. This holds true for the Eico 1030 and the Paco B-12.
Dave - WA6VVL


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 Post subject: Re: 6l6GC Replacement tubes for Heathkit IP-17
PostPosted: Feb Wed 13, 2019 5:46 pm 
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Joined: Aug Tue 28, 2007 6:44 pm
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Location: Tustin,CA
Incidentally, this subject has been discussed before..
viewtopic.php?f=8&t=336304
Dave - WA6VVL


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 Post subject: Re: 6l6GC Replacement tubes for Heathkit IP-17
PostPosted: Feb Wed 13, 2019 7:34 pm 
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Location: Sherman Oaks, Ca. 91411
Don Cavey wrote:
NW2K wrote:
Don Cavey wrote:
I know that this is straying a bit off topic but my understanding is that the 6BG6GA is approximately the he same as a 6L6GC.


Regarding plate dissipation, the RCA and GE datasheets for the 6BG6-GA give 20w. 6L6GC is 30w.
So, closer to the 6L6GB/5881 then I guess. Oh well. I didn't have the RC-30 handy. Thanks for pointing that out.


The later production Philips/ECG 6BG6GA tubes have 35w rated plates and are available for $18 a pair. I don't know if they will fit in an IP-17 though. BTW, I restored an IP-4 years ago and it had Hitachi 6L6GC tubes in it. From the date codes and appearance of the tubes, I think they were original to the unit.


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 Post subject: Re: 6l6GC Replacement tubes for Heathkit IP-17
PostPosted: Feb Wed 13, 2019 7:49 pm 
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Joined: Aug Tue 28, 2007 6:44 pm
Posts: 483
Location: Tustin,CA
Hi,
PS-4s that I have worked on have had Heathkit branded G.E. 6L6GCs, IP-32s almost exclusively red and yellow silkscreened Hitachi 6L6GCs, and G.E. 6L6GCs in IP-2717As.
Dave - WA6VVL


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 Post subject: Re: 6l6GC Replacement tubes for Heathkit IP-17
PostPosted: Feb Wed 13, 2019 10:15 pm 
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Yes... looking back through my notes, the unit I restored WAS an IP-32 - not a PS-4. It definitely had Hitachi 6L6GCs in it.


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 Post subject: Re: 6l6GC Replacement tubes for Heathkit IP-17
PostPosted: Feb Wed 13, 2019 10:29 pm 
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Joined: Dec Thu 13, 2018 7:55 pm
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Johnnysan wrote:
The 5881 is a good replacement for the 6L6GB, but not the GC. It may 'work' in the IP-17 but is not rated at 30 watts. The output of these power supplies is 100ma maximum.
As I said, I have never seen the Mullard 6L6 in a Heath as original, and I have worked on plenty of them.


Yes 100mA you there are 2 tubes no ?


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 Post subject: Re: 6l6GC Replacement tubes for Heathkit IP-17
PostPosted: Feb Thu 14, 2019 10:02 pm 
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Joined: Oct Fri 12, 2018 11:07 am
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WA6VVL wrote:
Incidentally, this subject has been discussed before..
viewtopic.php?f=8&t=336304
Dave - WA6VVL


Thanks for quoting the link Dave. I really liked that Eico 1030. It seems to be a much better buy than the Heath since it costs like $10-20 more than an IP-17. That AC fan setup is also really cool! The small AC fans I have are some vintage System Papst ones, though they are small they are little heavy since they are made of metal and loud too. But I'll try to add a flip switch and get one in! :mrgreen:


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 Post subject: Re: 6l6GC Replacement tubes for Heathkit IP-17
PostPosted: Feb Thu 14, 2019 11:13 pm 
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Joined: Aug Tue 28, 2007 6:44 pm
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Location: Tustin,CA
Hi,
Bench-testing the PS-4, IP-32, IP-17, Eico 1030, or Paco B-12, reveal near-identical results, so your choice kinda boils down to cosmetics. I have put that Globe fan in every one I have rebuilt in the last 10+ yrs, including an SP-2717A. My personal preference, however, favors the PS-4/IP-32 because it's a two-transformer design and I feel that those transformers are very conservatively designed. A pair of 6L6GC tubes matched with a MaxiMatcher should last a very long time, and several sellers on eBay are offering that matching capability. Replacing all those filter caps is also mandatory..
Dave - WA6VVL


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 Post subject: Re: 6l6GC Replacement tubes for Heathkit IP-17
PostPosted: Feb Fri 15, 2019 9:19 pm 
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Joined: Oct Fri 12, 2018 11:07 am
Posts: 92
WA6VVL wrote:
Hi,
Bench-testing the PS-4, IP-32, IP-17, Eico 1030, or Paco B-12, reveal near-identical results, so your choice kinda boils down to cosmetics. I have put that Globe fan in every one I have rebuilt in the last 10+ yrs, including an SP-2717A. My personal preference, however, favors the PS-4/IP-32 because it's a two-transformer design and I feel that those transformers are very conservatively designed. A pair of 6L6GC tubes matched with a MaxiMatcher should last a very long time, and several sellers on eBay are offering that matching capability. Replacing all those filter caps is also mandatory..
Dave - WA6VVL


The fan is a good choice because both the gas tube regulator and the zoners in the 2717 get pretty hot and the later burns the board if soldered too close. But doesn't the IP-17 also have a two transformer design. One transformer for the filaments and the other for the plate and bias? Yes, getting the matched seems to be important from what I learned from this post or I rock damaging the other tube due to the other one getting overloaded. I'll need to try to find a matched one for the spare Sylvania 6L6GC I have if possible. Or I'll go for a Tungsol as they don't cost an arm and leg like the American tubes!

As for the caps I was told they were changed back in 1999 or 2000. But re-capping it is still good since the caps run at pretty high voltages.


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