new el34s for apache

[NR5P]

I had one of the el34s in my apache short out some time back.  I'm looking for an affordable set of el34s that will be fairly reliable.  Since the apache runsem kinda hard I didn't want to have to buy another set shortly in the future.  Also don't want to spend more than I have to.

[N4LTA]

I'd try to get a pair of the older Svetlanas. They were pretty rugged. Circle C is the new Svetlana branding.

Pat
N4LTA

[sndtubes]

I'm in the tube business and you will find the old stuff on my website, but you won't like the price.  The audio people have driven the price of these through the roof.  I'd never pay my own prices (hi hi).  Unless you find a "steal" or are prepared to pay the huge money, the Russian stuff that Tube Depot and others sell are fine.  I'd stay away from Chinese, though.

[WBear2GCR]

Dunno about the latest Ruskie tubes, but the ones that were coming through 10 years ago would not take the abuse of the screens that the NOS USA tubes will. So, make certain that you have a means to control excess screen current. Once those tubes were "hit" hard (WRT the screens) they would start to bias drift and the current would rise. Bias them down, and sooner or later the current would rise... etc.

They may have fixed this in the current tubes, it seems likely since I've read better reports about the Ruskie tubes in recent times...

              Maybe you want to sub in some sweep tubes?

                              _-_- bear

[W3SLK]

Hmmmm, I never seemed to have problems finding good 6CA7's for my TX-1.

[ke7trp]

Tubesandmore.com  has a host of them. I would try to find american tubes. Then maybe the Svetlanas.

C

[WD5JKO]

These are mules, the Teslovak E34LS from Penta Labs:

http://www.pentalabs.com/pdfs/EL34S.pdf

Matched Set:
http://www.pentalabs.com/Product.aspx?dept_id=1516&pf_id=e34ls%20mp

I've tried them in RF amp Ab1 service. Not a great RF tube, but some of the other Russian ones I tried got gassy after a brief overload. This E34LS takes it and more....very stout!

I found that the 7591 is a much better RF tube (low Cgp), and two of those gave me 60w PEP on 80m in a QRO Central Electronics 20A. The EL34/6CA7 family are best left to audio usage. That E34LS survived a major rise in G2 voltage and took several seconds at about 100w Pd before it blushed. I think it has the 6L6GC tri-metal plate design..

Jim
WD5JKO