The tube in that link is the brown base , it is the less favorable of the two Chinese factories. Tom W8ji has explained the failure rate between one and the other.
I haven¡¯t used the brown base type in years.
Are cheaper though.
Again I will note that all of the white base ones come from the same factory.
73
Scott
MOn 2024-05-19 10:20, Alan - W5ARM wrote:
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[Edited Message Follows] _On Sat, May 18, 2024 at 11:52 AM, Joe -
W7RKN wrote:_
_It appears I have a shorted 3-500Z tube in my AL-82 amplifier._
_It also appears that right now the 3-500Z or ZG tubes are
unobtainium._
_..._
3-500's are nowhere near the "unobtanium" status. Getting expensive
now? Yes... but still quite readily available. While the original
Eimac's are getting harder & harder to find (and those that are
available are quite old), the Chinese ones are fairly plentiful.
Not sure about the reliability/longevity of the Penta-brand tubes.
They've been around a while, but the company itself is a bit checkered
(their "facilities" in the greater LA area have changed locations many
times in the last few years). The same "company" (location) also sells
the "Machlett" brand (although they are also ChiCom). I also now see
the "Amperex" brand being sold (eBay), but they too are no longer a
US-made tube... "assembled in China".
Henry Radio in Los Angeles sells a ChiCom version (a 3-500C) for a
fair price, and it comes with a one-year "guarantee". I've been
running a pair of these in a couple different amps (swapping them
between a Drake L-4B, and a Henry 2-KD Classic) for a couple of years,
without any issues.
They can be ordered direct from Henry radio, HERE:
I have no affiliation nor interest with them, just a satisfied
customer (I own a few Henry's!)
Good luck!
ON EDIT: Sorry for the multiple edits. For some reason the Henry tube
link wasn't working... My appologies.
--
73,
~Alan
Links:
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[1] /g/ham-amplifiers/message/40396
[2] /mt/106173952/8135091
[3] /g/ham-amplifiers/post
[4] /g/ham-amplifiers/editsub/8135091
[5] /g/ham-amplifiers/leave/12941173/8135091/773995006/xyzzy
