I have a strange problem with a HT30CD that's kicking my butt. The original Tube that was shipped with the unit works fine (other than being old and only makes 70 percent). It was retubed about 7 months ago with an Econoco that worked fine until now. The bias fault light came on. It is shorted with the econoco. When the tube is removed, the short goes away. With the tube out and measuring resistance on the tube itself, there is no short. We had econoco send a new rebuilt. It does the same thing. I've lookedover the tube socket and found nothing that looks unusual or suspect visually. The only think I have noticed is about a 1/8 of a inch difference in overall height of the econoco vs the original tube, and that the rings on the outside of the original tube are beveled and the econoco are not. Is it a problem I'm not seeing in the tube socket or is this darn thing that picky that beveling or a small length difference could cause such an issue? Thanks!
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Harris HT30CD challenge
- Thread starter KRXOEngineer
- Start date
As a side note I sure wished whomever designed this thing, among other things, would have used some brass screws instead of stainless everywhere. Stainless on stainless is just a nasty recipe for gousing!
4cx20000D
Did you specifiy to Econco that it is an HD30CD? I found I had to specify to them on Continental transmitters or I would get odd things happen.
I would check the tube socket again. You may need a mirror to get a real good look. The finger stock is very delicate, and can get bent very easy. Have you talked to Harris and Econco? The physical dimensions of a tube, important; see below!
Physical dimensions of the tube are extremely important! Seeing that it is a Harris tetrode, neutralization is important to the overall tube performance. Ten years ago, I could buy 10 Econcos and install them without re-neutralization and coarse plate adjustments. No more. Just about every tube now requires major neutralization adjustments, as well as coarse plate changes to keep the tube cavity resonate. This is not just one transmitter, but six different HT series transmitters. Other engineers I know that use Harris transmitters have experienced the same problems. Tube quality is terrible these days. You have to stress with Econco that you want an Eimac tube body. They have some rebuilds with Russian bodies. The same goes for Freeland. I tried Freeland with horrible results. Ended up back at Econco. You really have to complain and tell them you want a very good rebuild. Be sure to document your troubles by recording the tube serial numbers. As much as I love tube transmitters, I would never recommend any brand of new tube rig again. They are too much work and maintenance compared to a Nautel.
Physical dimensions of the tube are extremely important! Seeing that it is a Harris tetrode, neutralization is important to the overall tube performance. Ten years ago, I could buy 10 Econcos and install them without re-neutralization and coarse plate adjustments. No more. Just about every tube now requires major neutralization adjustments, as well as coarse plate changes to keep the tube cavity resonate. This is not just one transmitter, but six different HT series transmitters. Other engineers I know that use Harris transmitters have experienced the same problems. Tube quality is terrible these days. You have to stress with Econco that you want an Eimac tube body. They have some rebuilds with Russian bodies. The same goes for Freeland. I tried Freeland with horrible results. Ended up back at Econco. You really have to complain and tell them you want a very good rebuild. Be sure to document your troubles by recording the tube serial numbers. As much as I love tube transmitters, I would never recommend any brand of new tube rig again. They are too much work and maintenance compared to a Nautel.
In analog service,I've had good luck with Econco and Freeland rebuilds. Over the last few years, Freeland has shown themselves much easier to deal with, so they get the nod. Use them in an HT 30 and several Collins/Continental 3 bay radios. I got an HT/HD which ate the final recently at the three year mark. I polled several people, none had had any luck running rebuilds in HD service. So we got a new tube. Performs well, tuned up to the book numbers easily.
I'd hook my trusy ohmmeter to the scren ring with the socket empty, then watch it as I plugged the tube in. Any movement is a faulty socket someplace, look till you find it. That tubes with different dimensions give different results gives you a direction to start looking.
I'd hook my trusy ohmmeter to the scren ring with the socket empty, then watch it as I plugged the tube in. Any movement is a faulty socket someplace, look till you find it. That tubes with different dimensions give different results gives you a direction to start looking.
Thanks for the pointers!
This doesn't contribute to the solution, but having used Econco tubes with stellar results for as far back as I can remember, I did try a Freeland tube about 2 years ago. Ran great for a little over 2 years & the filament opened (I've never seen a filament open on a ceramic RF tube)...and it was operating below it's rated filament voltage at the time it failed. Think I'll continue to play it safe with Econco.littlejohn said:
It turns out it was two "bad" tubes. One had the bias issue, and the other had an open filiment it appears. Tube #3 from Econco worked great. They are "taking care of it". 
I was just a bit supprised to get two unusable ones in a row. Maybe it was off the before-the-holiday run or something. LOL!
I was just a bit supprised to get two unusable ones in a row. Maybe it was off the before-the-holiday run or something. LOL!
OKCRadioGuy said:It turns out it was two "bad" tubes. One had the bias issue, and the other had an open filiment it appears. Tube #3 from Econco worked great. They are "taking care of it".
I assure you, you're not alone. I've had similar luck with Econco lately. Sent one back recently that also had open filament. Got another one whose tuning was so vastly different, it would have required moving the shelf in an HT35CD, and if you have an HT30, you KNOW how much fun that is. Sent it back, and got another one back (maybe the same tube, who knows) that was off by the same amount. Had to move the shelf to get the tuning right.
Used to get tubes shipped double-boxed with Shock-Watch & tip sensors attached to them.
Now they show up in little boxes with maybe 4" of foam.
We did get a tube last year with an open filament that also had shorted elements. It's not supposed to make a metalic klunk when you turn it over,
Now they show up in little boxes with maybe 4" of foam.
We did get a tube last year with an open filament that also had shorted elements. It's not supposed to make a metalic klunk when you turn it over,
The trickiest part I guess is that a person assumes after tube #2 that it's something with the tube socket. It gets interesting because it can be a pretty complex diagnosis to figure out. Hopefully they've got a handle on it now. If not, I'll have to explore other options when it comes time to replace this one. We shall see...
No foolin'. I dumped Econco when I could no longer get someone on the phone who had English as a first language. Since Ihave a pronounced Southern drawl, we were unable to communicate. Idon't buy from folks I can't communicate with. The Freeland family is still small enough and interestd personally enough to take care of business.
That jogs my memory...Econco sent me 2 5CX1500B's maybe 6 months ago...one for immediate use, one for stock. The first one put out power galore--lots of headroom--for a few days & then dropped off to 50% of licensed power. I then put the other one in...it blew the screen supply fuse. Put the old one back in & it ran fine, albeit at 90% power. Econco tested both tubes, said there was nothing wrong with either one & sent me 2 more, both of which appear to be OK. I've trusted Econco for decades...now, not so sure. Has Debbie left Econco? She spoke wonderful English.OKCRadioGuy said:It turns out it was two "bad" tubes. One had the bias issue, and the other had an open filiment it appears. Tube #3 from Econco worked great. They are "taking care of it".
It might be time to make a change to Freeland. It's sad that QC seems to have dropped at Econco...
Only thing that worries me about that is that for the first time in my 43 year run at this, I had a filament open a week or 2 ago...and it was a Freeland tube.OKCRadioGuy said:
Econco was bought by the manufacturer of Eimac, right? Before that, Econoco had started making their own new tubes. After the buyout, Econco stopped making new tubes.
There's a small newer company in the same area that rebuilds tubes, and they are the people who used to work for Econco, but I don't recall who they are...
There's a small newer company in the same area that rebuilds tubes, and they are the people who used to work for Econco, but I don't recall who they are...
Zonum....headed up by Manuel Munoz, formerly of Econco.
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