Discussion in 'Amateur Radio Amplifiers' started by VE2GCE, Mar 28, 2019.
I'm not aware of any 3-500 tubes made in the USA anymore, and they haven't been in quite some time.
Yes, only Chinese made. But, they are proven very good tubes.
If you had said just "good" instead of "very good" I'd probably agree with you.
You can't buy new American-made 811As or 572Bs, either -- or just about any glass tubes.
I've found the Chinese 3-500ZGs are fine, but for some reason I'm hungry an hour later.
At least you don't have to replace the tube an hour later.
My "RFP" branded Chinese tube in my AL-80B has been in there for 9 years now of pretty frequent use and still works fine.
You can always buy gassy NOS Elmac 3-500Z.
An older one may even be OK. I've got an RFP branded tube in my AL-80b and it's 7 years younger than Steve's. Seems like it will be fine. I recently dusted off the insides of the amp and the tube looks brand new. I push it pretty hard sometimes too with AM service.
I have some original Eimac 3-500Z tubes and some RF Parts Chinese models. The Chinese tubes put out about 10-15% more power. Both work fine.
With 3-500 tubes it’s really a non-issue nowadays, especially if you pay the extra bucks to let RF Parts do the testing of them (and warrant them). If you try to get bargain basement tubes off eBay you may have varied results, since you become the test pilot, but you save a few bucks. Just don’t buy the cheapest ones you can find and then complain that your Yugo tubes don’t live up to your Mercedes expectations. This is very common in Amateur Radio.
I would trust RF parts.
It only cost a little more to go first class.