Any Used Solid State FM TX's Available?

[88.9 Miracle]

It goes beyond the power issue. I have experience working on Solid State units, not tube.

So back to my original question. I'm looking for a used 3-5kw solid state unit. Does anyone have a decent unit for sale at a good price?

 

[88.9 Miracle]

Oh and I forgot, you are a cocky ego driven engineer used to spending everyone else's money on high priced transmitters that don't break down so that you can sit on your a$$ and do nothing while collecting a check. It's their money right, not yours. Makes your job that you get paid for alot easier, right?

I own 3 stations, how many do you own? I think I'm in a better position to make this decision than you, right. Since I'm President of this Corporation. Unless you want to pay for the Transmitter. In that case I'll listen to you. Do you really think that I have not consulted others. Geez.

 

[SkyWolf]

Good god, all that over a question....if you aren't able to help someone then keep your trap shut. Ego makes me sick, some ppl think they are a gift to world with their unbelievable knowledge. Didn't know he asked for advice; the man is looking for a transmitter not your smart A$$ ego.

 

[Bengalsfan]

It goes beyond the power issue. I have experience working on Solid State units, not tube.

You are only wanting to replace your functioning transmitter with another one because you cannot work on your existing functioning transmitter. Yea, that makes real good business sense.

Oh and I forgot, you are a cocky ego driven engineer used to spending everyone else's money on high priced transmitters that don't break down so that you can sit on your a$$ and do nothing while collecting a check. It's their money right, not yours. Makes your job that you get paid for alot easier, right?

Your theory has one, small, problem. I don't make money on transmitters that work. I make my money on "good" businessmen like yourself that like to cut corners.

I own 3 stations, how many do you own? I think I'm in a better position to make this decision than you, right. Since I'm President of this Corporation. Unless you want to pay for the Transmitter. In that case I'll listen to you. Do you really think that I have not consulted others. Geez.

You are in the position to waste as much of your money as you like. It's too bad that you are getting upset and stomping your feet like a little child because you don't like what I'm saying, instead of listening to the advice of someone who's been in your position and telling you that you are making a mistake. Again, you want to spend the money and purchase some transmitter that is built on a island in the middle of the Mediterranean, then by all means, go ahead. Like I said, I don't make my money on transmitters that work. Me, or one of my friends, will be around to bail you out in a few years when your great deal turns into a dud.

Question for Skywolf. Didn't you say if you aren't able to help someone then keep your trap shut? So, how exactly did you help here? It's too bad that Bill didn't like the advice he was given. But wasn't that what he came in here looking for? Right? Advice on buying a transmitter.

 

[88.9 Miracle]

Question for Skywolf. Didn't you say if you aren't able to help someone then keep your trap shut? So, how exactly did you help here? It's too bad that Bill didn't like the advice he was given. But wasn't that what he came in here looking for? Right? Advice on buying a transmitter.

Actually I didn't ask your advice or anyone's advice. I posted that I was looking for a used transmitter. Better start reading from the top next time.

 

[Fieldtech1]

RockNuts,

Is there any way you can go higher in HAAT ,or, are you already at the top of the tower? Going higher in HAAT is what some freinds of mine did with a class A build. They are using a 1.5kw TX into a 6 bay antenna at around 150m HAAT for 2.4 KW ERP. This saved them a good bit of money both on inital build cost, and later in power cost by only needing a 1.5kw transmitter and have been happy with the end result.

 

[OKCRadioGuy]

Here's something to consider. Saving upfront may not be in your best interest. If your a small market guy, you're probably paying a contract engineer to fix things. IF he can fix it, there's a great chance you'll get billed for lots of hours to repeatedly fix a dog. Also, getting parts and support can be a big issue. A used Harris z or zx or a Nautel would be a safe bet instead of a gamble for you. Do yourself a favor and capex the right product for the job. Let me ask you a question. You admitted your old Harris tube rig still works fine for you, right? How old is it? Excellent engineering of that beast from the start paid off for you, didn't it? Do the right thing for YOU and keep your cost of ownership low. You know why I try to always select quality for my clients? Because I want them to be friends that occasionally need a bit of help instead of being in their wallet all the time which pisses them off. Whatever you do, keep that backup rig there and going, especially if your buying the 8k rig.... Off the air sucks more for you than your contract engineer. Heck, he gets paid for it, although I'm sure it would be annoying. Ultimatley you're the one that gets hurt cutting corners.

 

[bossbill]

I've been trying to follow the posts, but I'm confused. Since this is an engineering board, I have to assume we all have some engineering knowledge. On an engineering board, if someone posts something that seemingly doesn't make sense, do we say something or let it slide?

Most FM stations use CP antennas. A six-bay half-wave CP would have a power gain of 1.92 approximately. A horizontal only would be closer to 4.

What does the "antenna building" have to do with gain? You have power gain, line loss, and TPO, for a total of 10 kw. Right?

The way I read the "made in China" link, looks like the Chinese want $16k for the 3kw solid-state transmitter. Either that, or you get 5 of them for $16k. Now that would make sense. Buy 5, sell 3, keep one for spare, because your might not get overnight service. I just bought an exciter from China. Damned if I know why. It has a small problem and I think it takes the seller several hours each time just to translate replies to my emails.

Poster is correct on power consumption. I used to sell BE transmitters and Harris transmitters. We sold FMs for reasons other than power savings. Good reasons are lack of tubes and redundancy. Other poster also correct. Add some height, and in most cases, more bays. Better line-of-sight and less TPO.

 

[88.9 Miracle]

Poster is correct on power consumption. I used to sell BE transmitters and Harris transmitters. We sold FMs for reasons other than power savings. Good reasons are lack of tubes and redundancy. Other poster also correct. Add some height, and in most cases, more bays. Better line-of-sight and less TPO.

Bill we will acheive MUCH more gain on this antenna than 1.92 because it is directional antenna. The final gain will not be known until they complete the building of the antenna and test it. We should easily be able to meet our 10kw ERP with 3kw or less. This per PSI.

 

[Bengalsfan]

Actually I didn't ask your advice or anyone's advice. I posted that I was looking for a used transmitter. Better start reading from the top next time.

You know what. You were right. I made the mistake of trying to point you in the right direction when in reality, you were just trolling the forum for equipment.....again. I'm just so used to working with broadcasters that can see further in the future than the next 12 months. And they understand the importance of making wise investments on equipment that you can get service and support on. It's your radio station and you have the legal right to make foolish decisions. So by all means, don't let anyone try to make you see the big picture, Bill.

Like I said, I don't make money on transmitters that work. Me and my fellow contract engineers make money on people like you.

 

[TomT]

Bill..when we replaced our Harris 2.5 with a 2.5 kw Nautel we noticed a considerable drop in power consumption. However, had to give up some of that gain in power costs because the Nautel (a V-2) didn't get enough ventilation once summer arrived. Chopped a hole in the block wall and put in a large window air conditioning unit to blow on it and keep it happy.

When shopping solid state transmitters, look at their ventilation. They tend to put these things in boxes that are a bit too small just for marketing purposes. Ideally, there should be lots of holes in the front panel since that is where the cool(er) air will be coming from.

 

[Bengalsfan]

Off the air sucks more for you than your contract engineer. Heck, he gets paid for it, although I'm sure it would be annoying. Ultimatley you're the one that gets hurt cutting corners.

I tried explaining that to him, but he doesn't get it. He'd rather have his "secret" deal for a transmitter that saves him money upfront than have a reliable rig that saves him money in the long run.

 

[88.9 Miracle]

Bill..when we replaced our Harris 2.5 with a 2.5 kw Nautel we noticed a considerable drop in power consumption. However, had to give up some of that gain in power costs because the Nautel (a V-2) didn't get enough ventilation once summer arrived. Chopped a hole in the block wall and put in a large window air conditioning unit to blow on it and keep it happy.

When shopping solid state transmitters, look at their ventilation. They tend to put these things in boxes that are a bit too small just for marketing purposes. Ideally, there should be lots of holes in the front panel since that is where the cool(er) air will be coming from.

Hi Tom,

Yes I've got a 2.5kw solid state at one of my installations and we do indeed have plenty of air being blown inside the unit. We're using 4 rack mounted blowers as well as a 25,000 BTU A/C unit in the wall keeping the unit nice and happy.

I am wondering though, and this is a question I've been meaning to ask on this board, if I end up using the 4kw Harris tube, housing it in a 16X16 foot building, will a large fan exhaust system be enough to keep it happy or should I install AC there as well. I've been told that Tube TX can withstand a higher amount of heat. Any insight on this would be appreciated.

Should we elect to use our Harris 4kw unit, is there any engineer interested in getting the unit air ready for us? We're only about 6-8 weeks away from flipping the switch. I'd be happy to meet with you and talk about the project and your fees. You can email me off-board at [email protected] if interested.

 

[88.9 Miracle]

OKCRadioGuy

For the record we won't be buying the $8,500 TX because it is an import and I have obvious concerns about that. The 4kw Harris I purchased used and needs some work done to it to bring it to air-ready. I've had it in storage for a year or so and have never fired it up.

I may well end up using it, but I simply would rather have a used Solid State in working condition if the price is right. Ultimately I would love to have a new unit. Heck I'd love to purchase a Nautel but we don't have a ton of cash to put into one of those units right now. It's a non-comm.

I don't pay an engineer. I do it all myself including programming, accounting, you name it. This will be the 5th station I've built. I've currently got 2 on the air and two others that I manage. Our largest expense by far is the Directional 6 Bay.

FIELDTECH

We are already at the top of the tower. Can't go any higher on this stick. PSI says we'll be able to achieve our 10kw ERP with roughly 2.8kw TPO, give or take.

 

[littlejohn]

Directional.. 'splains the strange gain. Thanks.
Point to ponder - >if< you use the tube radio and run it on ambient air, don't pull air into the building via an exhaust fan. Instead, push it in with an inlet fan and filters. That way, the building is pressurized, all the air comes in through filters, things stay cleaner, and the transmitter stays (marginally) cooler. The fan, louvers, and filters cost exactly the same either way. Where 'bouts are you building this thing, anyways?

 

[88.9 Miracle]

Directional.. 'splains the strange gain. Thanks.
Point to ponder - >if< you use the tube radio and run it on ambient air, don't pull air into the building via an exhaust fan. Instead, push it in with an inlet fan and filters. That way, the building is pressurized, all the air comes in through filters, things stay cleaner, and the transmitter stays (marginally) cooler. The fan, louvers, and filters cost exactly the same either way. Where 'bouts are you building this thing, anyways?

Interesting on the fan you recommend. So the air system should suck the air into the building and the output would simply be vented out of the building by a vent? Do you have pictures of such a setup you could share? Can you suggest particular equipment (web links)?

My big question is will a 16X16 foot building be large enough to displace the heat created with a 4kw tube? Should the ceilings be 8 feet or 10 feet or higher (to get the heat to rise way above the unit and then pushed out of the building via the fan system)? How large of a fan should be purchased? Will AC be needed at all?

We are building the station right now in Verona. The tower will be up in the next week.

 

[TomT]

We have a Harris 10 K in a smaller building--about 9 X 16--been there for years (installed 1988) here in northern WV. Perfectly happy.

We have three "tunnel" type blowers blowing air in, and four attic fans flowing air out. The blowers and fans are set with different thermostat levels so they are not all running all the time. We allow the Harris to vent unrestricted into the building--don't try to duct it, let it breathe. There is a filter box on the outside of the air intake--does need maintenance, as gets clogged up by bugs and (mowed) grass in the spring and summer. We just use standard furnace filters (in addition to the filter on the transmitter's air intake).

Plan air flow carefully so that there is good air circulation through your equipment rack. We have two STL's, two audio processors (Omnia 3's), a Continental 802A and a MX-15 all running at once in a 6' rack. (We feed a second station with the STL's, the MX is an exciter for a 2.5K backup transmitter). We added a fourth attic fan as hot air was "pooling" in that corner of the building.

 

[rrsounds]

Directional.. 'splains the strange gain. Thanks.
Point to ponder - >if< you use the tube radio and run it on ambient air, don't pull air into the building via an exhaust fan. Instead, push it in with an inlet fan and filters. That way, the building is pressurized, all the air comes in through filters, things stay cleaner, and the transmitter stays (marginally) cooler. The fan, louvers, and filters cost exactly the same either way. Where 'bouts are you building this thing, anyways?

I'm with littlejohn here.
Positive air pressure is the way to go for reduced long-term dirt-related maintenance and its costs. I would also suggest that a very large cross-section input filter (or a number of parallel filtered openings) will allow an aggressively fine filter mesh at a reduced airflow velocity (which reduces filter clogging), whose end result will be to greatly reduce dust in the room and its accumulation where it can't be tolerated in the transmitter. You may want to add temperature-controlled louvers on the fan(s) to allow the transmitter to heat the room in the winter time.

Should you decide to go this route, you may want to talk with an HVAC guy who could do the basic sheet metal work to put it all together. See if he can set it up so your filter holder(s) are a standard size, so you can easily find replacement filters at a reasonable cost at Lowe's/Home Depot or wherever. Then replace them regularly. They really do pay for themselves.

If you do not have too many 95-100 degree days, you may be able to get away with no A/C at all, but of course that is my opinion (cuz solid state boxes are nowhere near as heat-tolerant as thermionic ones), and YMMV.

Kind Regards,
David

 

[MickeyD]

Oh and I forgot, you are a cocky ego driven engineer used to spending everyone else's money on high priced transmitters that don't break down so that you can sit on your a$$ and do nothing while collecting a check. It's their money right, not yours. Makes your job that you get paid for alot easier, right?

I own 3 stations, how many do you own? I think I'm in a better position to make this decision than you, right. Since I'm President of this Corporation. Unless you want to pay for the Transmitter. In that case I'll listen to you. Do you really think that I have not consulted others. Geez.

Your transmission chain is the most important part of your radio or TV station. If you cut corners there your signal will suck. If you are on a budget, cut corners in your studio or office space.

 

[rfry]

If you do not have too many 95-100 degree days, you may be able to get away with no A/C at all, but of course that is my opinion (cuz solid state boxes are nowhere near as heat-tolerant as thermionic ones), and YMMV.

Good advice to check on such ratings for the products of all transmitter manufacturers.

In the example cases of the Harris HT-20CD 20 kW FM transmitter using a single vacuum tube PA, and the Harris ZD-20CD 20 kW all solid-state FM transmitter, both of those designs are spec'd for a maximum tx inlet air temperature of 50 degrees Celsius (122 degrees Fahrenheit) to meet all other performance specifications for those transmitters -- de-rated by 2 degrees Celcius per 305 meters AMSL.

RF (Harris Broadcast Division FM Product Line Appl Engineer, retired 1999)