[MRCA] [MMRCG] Econco

[Ray Fantini]

Use to do a lot of 4CX20000 tubes in higher power FM stations and found that a Econco rebuild lasted just about half as long as a new Eimac. But they cost half as much. Never did VHF TV but a lot of UHF and had a pair of Comark 30 kW analog (EEV)IOT transmitters that I loved. There was a real art to keeping them running, after power outages or having to be off line for some time it was a challenge to get everything back up and running at full power. But now that analog is gone have all these smaller ATSC transmitters that just have a ON/OFF button and require no skill to operate. 
Klystrons, IOT and Crowbars! I do miss that stuff.

Ray F/KA3EKH


-----Original Message-----
From: Jack Antonio <scr287 at att.net> 
Sent: Friday, February 13, 2026 11:38 AM
To: MMRCG at groups.io; Ray Fantini <RAFANTINI at salisbury.edu>; mrca at mailman.qth.net; milsurplus at mailman.qth.net
Subject: Re: [MMRCG] Econco


Working for a TV station, I received quite a few 4CX5000A from Econco. We had both a low band (CH-2) and a high band transmitter (CH-10). We found that in our transmitters at least, the CH-10 transmitter was happier with new Eimacs. The CH-10 was a conversion from CH-12, so that may have had something to do with it.

Jack Antonio
WA7DIA

On 2/13/2026 9:53 AM, Ray Fantini via groups.io wrote:
> Not directly Ham related but a sign of things to come, Microwave Power 
> Products the parent company of Econco located in Woodland, CA just 
> announced that they will be closing down operations of their repair 
> services for Power Grid tubes. They are just about the only source for 
> rebuilt things like 4CX3500 tubes that are used in a bunch of older 
> broadcast transmitters and may now force many radio stations to 
> finally replace their old tube transmitters. Don't think anyone has 
> built a high powered broadcast transmitter that still uses tube 
> technology in about twenty years now but there are still a lot of the 
> old Harris HT-3.5 and BE FM-5 out there. I was always able to pick up 
> good money changing tubes in those transmitters where the newer Gates 
> and Nautel transmitters just have PA panels that can be swapped by a 
> secretary, or the typical chief who is now days an IT manager.
>
> Some glass tubes like the 211 and 833 are still in production for the 
> audio market, think the current version of the 833 is the 833/FU-33 
> but it looks like the day of the ceramic/metal power tube is coming to 
> an end. Imagine for my lifetime things like the 4CX250 and 350 will 
> still be available NOS being you can still find 6D6 and 6C6 tubes 
> available NOS on eBay but other bottles like the 3CX800 become pricy 
> and you have to wonder how long they will stay in production? The 
> 4CX3500 was used in a large number of transmitters by several 
> manufactures but reached the point of no longer being economical to 
> rebuild or manufacture. How far behind can the 3CX800 be?
>
> Ray F/KA3EKH
>