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3-500 tubes
开云体育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. ? Sellers on eBay are selling new Penta tubes for a ridiculous amount of money. ? Are Penta tubes any good? ? Perhaps I should ask first, who has 3-500’s for sale? ? I am going to replace the T/R relay in the amp while I have it open….Been a weak component in the amplifier since it was new.? Been replaced twice now and the amp is only 4 years old. A friend who is? an amplifier guru is going to look into building an external, plug in, relay setup for me.? Then I could go to a vacuum relay and my T/R relay issues would be over!? Just to be on the safe side, I just purchased 3 relays from Ameritron (MFJ) to have when they are no longer doing business.? If I do the relay modification, the Ameritron relays should sell fairly quickly as it appears all their high power amps use the same relay. ? Thanks in advance, for any questions answered! ? Joe – W7RKN |
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Un obtanium ? What makes you think and then say that ?
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Penta and all the others are Chinese. Ones with the white ceramic base all come from the same factory, and are from the better of the two factories over there. Yes penta’s are good, also excellent customer service. 73 Scott MOn 2024-05-18 10:52, Joe - W7RKN wrote: It appears I have a shorted 3-500Z tube in my AL-82 amplifier. |
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On Sat, May 18, 2024 at 08:31 PM, Colin Kaminski wrote:
phone all three BOTH numbers on their contact list.? ?I got through to em....twice, 2 days ago.? MFJ Enterprises Inc:
Toll Free:?1-800-647-1800
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MFJ / Vectronics / Mirage:
Phone#:?1-662-323-5869
Tech Support/Part Orders Phone#: 1-662-323-0549
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Not sure why so many are freaking out about the closure and parts availability. All of the parts they carry are still in production.
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Most of them have other part options that will work in their place. Ameritron will also be around for at least another year . 73 Scott On 2024-05-18 12:51, Jim VE7RF wrote:
On Sat, May 18, 2024 at 08:31 PM, Colin Kaminski wrote:<I needed up adding a QSK-5 instead. There is at least one more onphone all three BOTH numbers on their contact list. I got through to |
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On Sat, May 18, 2024 at 06:52 PM, Joe - W7RKN wrote:
###? Cheapest price is HARBACH ELECTRONICS.....which re-opens on May 20....at the stroke of midnight EST. $275.00? each.? ?$550.00? for a matched pair.? ?Free shipping, no tax. ? These are the good ones, with the white base.? ? ? ? |
开云体育
The best appears to be from CTR engineering.? There are two plants that make 3-500 tubes in china. These are the best of the two.? They are fully Hi pot tested and guaranteed.? ?Mine have been rock solid.
I have had very bad luck with Penta.? Over and over failed or gassy tubes out of the box.? I ended up just getting a refund, They were nice to deal with, no trouble.? I was told they likely just got a bad batch.? Maybe they are better now. This was a year or
two ago.?
C
From: [email protected] <[email protected]> on behalf of Joe - W7RKN via groups.io <w7rkn.7@...>
Sent: Saturday, May 18, 2024 9:52 AM To: [email protected] <[email protected]> Subject: [ham-amplifiers] 3-500 tubes ?
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. ? Sellers on eBay are selling new Penta tubes for a ridiculous amount of money. ? Are Penta tubes any good? ? Perhaps I should ask first, who has 3-500’s for sale? ? I am going to replace the T/R relay in the amp while I have it open….Been a weak component in the amplifier since it was new.? Been replaced twice now and the amp is only 4 years old. A friend who is? an amplifier guru is going to look into building an external, plug in, relay setup for me.? Then I could go to a vacuum relay and my T/R relay issues would be over!? Just to be on the safe side, I just purchased 3 relays from Ameritron (MFJ) to have when they are no longer doing business.? If I do the relay modification, the Ameritron relays should sell fairly quickly as it appears all their high power amps use the same relay. ? Thanks in advance, for any questions answered! ? Joe – W7RKN |
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On Sat, May 18, 2024 at 09:11 PM, W7WRX wrote:
CTR gets his 3-500Z's from the exact same chinese factory as Pentalabs....and also RF parts.? ?These are the ones with the white bases.? ?Factory #2 is junk, with a 70% failure rate....and those all have brown bases.? Even tubes from the good factory all? just 1 kv hi-pot test? between grid and cathode.? (Eimac's are typ 5 kv from grid to cathode...and 16 kv from anode to grid).? ?The good chinese tubes have higher grid to cathode C? vs? eimac.? It appears the chinese tubes? have spaced the grid closer to the cathode vs eimac.? ? A month ago, everybody and their dog got a severe bad batch of chinese 572B's..... like the entire production was screwed up...... but the 572B is another, all together scenario.? |
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I have used thousands of 3-500zg penta tubes in customers pa’s. Not once have I had an issue or have any customers reported an issue.
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But I was putting new tubes into pa’s that I had gone through and made right. You can’t just plug tubes into a pa that could have any issue. The 572b tubes have issues now and then, but that’s a factory issue. Penta does an excellent job pre testing, but sometimes the 572b tube can still have an issue. Why I have the customer drop ship the tubes to me to test in their amp prior to shipping to them. Rather it happen here and not at their qth. If you have a problem with a penta tube they just replace it. Unless obvious abuse. They do t make you Jim through hoops. 73 On 2024-05-18 13:40, Jim VE7RF wrote:
On Sat, May 18, 2024 at 09:11 PM, W7WRX wrote:The best appears to be from CTR engineering. There are two plantsCTR gets his 3-500Z's from the exact same chinese factory as |
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And keep in mind
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I make zero, zip, nada off tubes my customers purchase and drop ship to me. So my statement is truly un biased. On 2024-05-18 13:11, W7WRX wrote:
The best appears to be from CTR engineering. There are two plants |
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And since 3-500Z tubes are zero-bias .... 73 Jim N6OTQ On Sat, May 18, 2024 at 2:54?PM Amp Guy Llc via <kb1sel=[email protected]> wrote: And keep in mind |
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Hi Scott...
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Don't know where you read that, but MFJ has been adamant about informing everyone that they will continue to sell parts in stock and support any warranty repairs, but once parts are gone, they are gone. They are no longer manufacturing parts. Joe - W7RKN -----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Amp Guy Llc via groups.io Subject: Re: [ham-amplifiers] 3-500 tubes Not sure why so many are freaking out about the closure and parts availability. All of the parts they carry are still in production. Most of them have other part options that will work in their place. Ameritron will also be around for at least another year . 73 Scott |
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Hi Scott...
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All the usual sources for 3-500 tubes are showing 'none in stock', therefore, 'Unobtainium' I had never heard of ct before. I will order from them or Harbaugh. Thanks for the info on Penta tubes. I've read and heard good and bad about them....in about equal numbers. Right now, a pair of good used Eimac's sound pretty good! Joe - W7RKN -----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Amp Guy Llc via groups.io Subject: Re: [ham-amplifiers] 3-500 tubes Un obtanium ? What makes you think and then say that ? |
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Hi Joe
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Ameritron does not make the meters , tubes , transistors , nuts , screws , spacers , electrolytic caps, rotary switches , resistors , air variable capacitors , transformers , switches , relays etc etc etc They buy these parts and many more from vendors. May have to buy in bulk for a few items but can still be had. Scott On 2024-05-18 15:54, Joe - W7RKN wrote:
Hi Scott... |
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You must be on the rf parts website
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If you call them they most likely have them. The site doesn’t get updated often. 73 On 2024-05-18 16:01, Joe - W7RKN wrote:
Hi Scott... |
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All,
I emailed Tom Rauch's company to ask about prices and availability on 3-500Zs and 572Bs. ? As it happens, I have a need for both, and Rauch has a rigorous incoming test procedure, and it's documented on his website. ?His website says that he checks email twice a day, so if he checks on Saturdays I may have an answer late today. ?I'll share what he says about getting tubes. ?? 73 Jim N6OTQ |
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3-500zg orders placed through the Harbach site will almost always ship within one business day.
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And if an issue comes up, penta is quick to replace. As long as within the warranty Period, and the tube has not been abused. On 2024-05-18 16:27, Jim Strohm wrote:
All, |
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On Sat, May 18, 2024 at 11:52 AM, Joe - W7RKN wrote:
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
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Colin Kaminski
Alan - W5ARM