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Title: Comparison of new 3-500Z triodes Post by: John K5PRO on January 25, 2006, 06:27:46 PM Attached is a short summary of my recent experience buying two 3-500Z triodes and their chimneys. "Caveat Emptor".
I hope the PDF format comes out. 73 John Title: Re: Comparison of new 3-500Z triodes Post by: K6IC on January 25, 2006, 10:27:32 PM Very Interesting, John. Thanks for the post. Will be looking for the post mortum on your tests.
73 Vic KF6RIP Title: Re: Comparison of new 3-500Z triodes Post by: Vortex Joe - N3IBX on March 29, 2006, 11:58:29 AM John,
I too, found it very interesting. Considering their warranty, I always though the "RF Parts" branded 3-500ZG to be a good tube. Regards, Joe Cro N3IBX Title: Re: Comparison of new 3-500Z triodes Post by: stansub on December 09, 2007, 06:37:50 PM When I purchase 3-500Z's, I buy Amprex, ONLY!!!! Never a problem. I have two amps using them, AL-82 and SB 221.
Title: Re: Comparison of new 3-500Z triodes Post by: Steve - WB3HUZ on December 18, 2007, 01:05:31 PM Been using the RF Parts ZG's for over five years in two different amp with no problems.
Title: Re: Comparison of new 3-500Z triodes Post by: Opcom on January 11, 2008, 11:06:08 PM I bought these Chinese 3-500ZG tubes from ESRC. The warranty begins when they are first put in service and is for a year. quite friendly. I tested them initially by dissipating 1KW DC in a pair with zero bias for 30 minutes. I found no hot spots and the currents were reasonably equal. The attachment shows the Chinese tubes in the modulator. There have been no problems. Image attached. Looks like the same tube sans the rectangular logo? AMfone - Dedicated to Amplitude Modulation on the Amateur Radio Bands
Had I received such an obviously defective tube as the one in the PDF, I would have returned it for a replacement. I do not like the vendor of the Chinese tube shown in the PDF because they are unfriendly. I bought some RF power transistors from them and discovered that they in effect have no warranty. I was told by that vendor that they test them beforehand and then it's on the buyer, because "people blow them up and return them". |