Harris HT-5 with MS-15 Exciter for Sale

[r0cknr0ll]

Pics available - in great condition. Make an offer above 6k if interested. Currently tuned to 105.5. Thanks!

 

[Bengalsfan]

I hate to tell you this, but an HT-5 isn't worth $6k. If someone offers you $2k for it, consider yourself lucky.

 

[BobOnTheJob]

I hate to tell you this, but an HT-5 isn't worth $6k. If someone offers you $2k for it, consider yourself lucky.

Any idea why used transmitters have so little value? With new 5KW's costing several times $6k, one would think that owners would be salivating at a cost savings like that...but as you pointed out, they aren't.

 

[Bengalsfan]

I hate to tell you this, but an HT-5 isn't worth $6k. If someone offers you $2k for it, consider yourself lucky.

Any idea why used transmitters have so little value? With new 5KW's costing several times $6k, one would think that owners would be salivating at a cost savings like that...but as you pointed out, they aren't.

In this case, Harris does not support this transmitter anymore. So you are buying an obsolete transmitter right off the bat. Another factor is the cost of running it. I just recently installed a new 2500 watt solid state transmitter in Jasper that has an efficiency rating of 89%! If I recall correctly, the eff rating on this transmitter is between 65 and 70%. Over time, that adds up. Also figure that you also will not need to run an air conditioning system with the solid state I just installed. And as I recall, the HT5s were hard on tubes. I was replacing them every couple of years in every HT5 I had. Freeland Products charges between $800-$1000 just to rebuild the 4CX3500A that the HT5 uses. Brand new they run about $2500.

Technology marches on. Asking $6000 for this rig will insure it sits where it is for a very long time. Were it me, I'd be willing to GIVE it to anyone who comes to remove it.

 

[Chuck]

I just recently installed a new 2500 watt solid state transmitter in Jasper that has an efficiency rating of 89%! If I recall correctly, the eff rating on this transmitter is between 65 and 70%. Over time, that adds up. Also figure that you also will not need to run an air conditioning system with the solid state I just installed. And as I recall, the HT5s were hard on tubes. I was replacing them every couple of years in every HT5 I had. Freeland Products charges between $800-$1000 just to rebuild the 4CX3500A that the HT5 uses. Brand new they run about $2500.

If I recall correctly, a lot of tube type transmitters are only efficient at or near their rated power. At least on I can think of (a grounded grid triode) drops below 60% efficiency when run about 2/3 power. Or so says its instruction manual.

 

[fm-engineer]

I hate to tell you this, but an HT-5 isn't worth $6k. If someone offers you $2k for it, consider yourself lucky.

Any idea why used transmitters have so little value? With new 5KW's costing several times $6k, one would think that owners would be salivating at a cost savings like that...but as you pointed out, they aren't.

In this case, Harris does not support this transmitter anymore. So you are buying an obsolete transmitter right off the bat. Another factor is the cost of running it. I just recently installed a new 2500 watt solid state transmitter in Jasper that has an efficiency rating of 89%! If I recall correctly, the eff rating on this transmitter is between 65 and 70%. Over time, that adds up. Also figure that you also will not need to run an air conditioning system with the solid state I just installed. And as I recall, the HT5s were hard on tubes. I was replacing them every couple of years in every HT5 I had. Freeland Products charges between $800-$1000 just to rebuild the 4CX3500A that the HT5 uses. Brand new they run about $2500.

Technology marches on. Asking $6000 for this rig will insure it sits where it is for a very long time. Were it me, I'd be willing to GIVE it to anyone who comes to remove it.

Maybe I'm wrong, but I think Harris still supports HT-5's. I never saw any HT's with MS-15 exciters, only THE-1 or Digits. The old FMK series had MS-15's. With the ever changing tube rebuilding qualities, neutralization became an issue with rigs such as the HT-5. For years, Econco's would work right out of the box. Today, no tube is ever the same, and most will require neutralization. The HT was a very simple design, and I never had too many problems with them. I still maintain both HT-5's and HT-10's. Efficiency can add up over time, I agree, but why replace a transmitter that was designed to last 20-30 years? The main enemy to tube rigs is the ever growing number of younger engineers who cannot work on them. Today, it's plug and play on modules. Don't get me wrong, I love my SS Nautels, but an amplifier is an amplifier.

 

[r0cknr0ll]

Here's the pictures of it in a zip file.

http://69.18.39.45/harrisht5.zip

 

[Lazy J]

It is certainly clean and in good condition. But as fm-engineer stated, us "younger engineers" (under 30), don't like to work on them. Not that we CAN'T, we just prefer not too.

 

[Bengalsfan]

It's not that I don't like to work on tube, I have several backup transmitter that use tubes, technology has moved on. Tubes are great for backup transmitters, but solid state rigs have the best effeciency. I think someone concerned about the bottom line would be foolish NOT to consider replacing an old tube transmitter with a newer solid state rig.

why replace a transmitter that was designed to last 20-30 years?

Just because it's designed to last 30 years does not mean you need to keep it as a primary transmitter for 30 years. again, technology has moved on. If you have an older, ineffecient transmitter, why not replace it. You think it would make sense to continue to drive a '79 Ford Ranger when an '09 Ranger is much more effecient? Cars are (or were) designed to last 30+ years, right?

Bottom line, rocknroll isn't going to get $6000 for the transmitter. I have seen FM10Ks go for about $7000. He's gonna be lucky to get $2000 for an HT5.

 

[fm-engineer]

Here's the pictures of it in a zip file.

http://69.18.39.45/harrisht5.zip

Not bad for its age and well maintained. Based upon the date tag of 1991, I can confirm that the exciter that would have been standard in that transmitter would be the (THE-1), which was a far better exciter than the MS-15. Actually, the MS-15 dates back to the early 80's. IIRC, the MX-15 was the exciter before THE-1. Just some observations: if this transmitter was taken directly off-air, it was not tuned properly. The plate tuning paddles should be meshed at 50%. This would confirm the tube cavity was not resonate, and would require an adjustment of the coarse tuning bar. Tuned correctly, with a good tube, into a good match, this transmitter is capable of synchronous noise of -50 to -55 dB, only a few dB less than a good SS rig. It also appears the blower has been rebuilt. Not too uncommon since a new one is very expensive. That is one of the older (blue case) IPA's. They seem to run forever until the solder points degrade on the Wilkinson combiner, resulting in a 50% loss of IPA drive. Just re-solder and drive on. With a modern exciter (Digit, etc) , that rig will perform equal to a SS rig in every category except efficiency. If you are buying a new SS rig, I would also buy a coax switch and make the HT-5 a back-up unit. It never amazes me at the number of sites with only 1 transmitter.

 

[jboyd]

Considering the posts, and that I am old time engineer...Here are questions:
1. What, if any is the minimum bid?

2. Where is it?

3. Single phase?

At the right place and price. I have interest. JBI

 

[TomT]

A THE-1 is essentially an MX-15 with a 50 watt power amplifier. The AFC/mod osc boards are essentially identical, except they are designed for a weird drop-in edge connector, rather than a conventional edge connectors.

The MS-15 is the predecessor to the MX, the AFC board in the MX was re-designed to compensate for the "Axel-F" phenomenon (do-do-di-do-dungggg.....hiss!).

A real PITA to work on. Been there, done that.

 

[frankberry]

I just noticed that the operating frequency of the transmitter in the photos is 101.7 ... not 105.5 as stated in the first post.
Has the transmitter been retuned for the 105.5 frequency?

 

[r0cknr0ll]

Yes - retuned to 105.5.

 

[OKCRadioGuy]

I called big H. Since we have an HT5 as our only transmitter at one site, I wanted to know if the box was still supported. It is. Support guy's guess is that it would be for another five years or so. We have a THE-1 exciter. The box has been very solid for us. The only problem I've had so far is the IPA regulator. I had a pretty crappy experience with Big H on that one, but that's a whole thread into itself. Otherwise it's been a great box. Oh yeah.... They refused to help me with the THE-1 exciter one night. Thats part of the reason I called Big H. It's still supported so I guess I just drew a real jerk that night. (they seem to have several these days) Good luck on selling the unit. It would make a fine backup rig for someone or effectively a co-main for someone like me that already has one. My room won't fit it and we are govt ran where I can't buy used, or I'd certainly try to!

 

[jboyd]

I have one too...but I can get no response from the owner. JBI

 

[Nostalgia]

I hate to tell you this, but an HT-5 isn't worth $6k. If someone offers you $2k for it, consider yourself lucky.

I've got no dog in this fight, but I did come across this listing on the Transcom website for another 1991 HT5 with THE-1 exciter:
Harris HT5* 5 KW 1991 Single Tube 89.7 $10,500 THE-1 Excellent

So the actual value lies somewhere between $10,500 and $2,000 allowing for differences in the exciter.

 

[bossbill]

It's been more than ten years since I was involved with Harris and BE, but an earlier post stated that there are solid-state FMs with 89% overall efficiency. Has efficiency gone up that much in ten years? We weren't selling solid-state FM for increased efficiency.

 

[fm-engineer]

It's been more than ten years since I was involved with Harris and BE, but an earlier post stated that there are solid-state FMs with 89% overall efficiency. Has efficiency gone up that much in ten years? We weren't selling solid-state FM for increased efficiency.

Nautel has some new fm's listed at 88%. Any piece of equipment that produces excess heat will suffer from degraded efficiency. Some tube rigs produce an extreme amount of heat which is wasted power. Some people use that heat to warm their transmitter shacks, but in the summer it is wasted power. Twenty years ago none of us would have bought SS FM transmitters. Today, SS has taken over the market. That doesn't mean everyone should remove tube boxes from service.

 

[rfry]

It's been more than ten years since I was involved with Harris and BE, but an earlier post stated that there are solid-state FMs with 89% overall efficiency. Has efficiency gone up that much in ten years? We weren't selling solid-state FM for increased efficiency.

Nautel has some new fm's listed at 88%.

Nautel makes some fine FM transmitters, and the 88% number might be possible at the level of a single power FET. But that value would be unlikely for the AC input to r-f output efficiency of the complete transmitter system.

The Nautel product line brochure for the new NV series of FM transmitters shows their overall AC to r-f efficiency to range from 61% for the 3.5 kW model to 64% at the 40 kW model.

Just to note that these numbers are almost identical to those for the same power level range of Harris "Z series" FM transmitters when they were introduced over ten years ago.

(Disclosure: posted by a retired Harris Broadcast FM Applications Engineer)
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