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Groove1670
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Which do you use. Pro and cons. Power consumption. ease of repair etc. Have you decided to stay with a tube transmitter.
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At the higher power levels, the tube units still get the nod because they are less complex and consequently less expensive. Other than tube replacement about every three years, the maintenance is a wash. The power burn for blowers is about offset by the better efficiency of the tube boxes.
Over the years, the cost of transistor radios has become reasonable at succesively higher power levels. Currently around 10KW is about the tipping point, however Harris says they will compete up to 20KW with their newest product. Nautel weill surely follow, as will Continental. We should be anticipating a new group of transmitters shortly.
For clarification, I refer to FM systems. Transistor AM radios have been cost effective up to the 50KW power level for some time now.
Over the years, the cost of transistor radios has become reasonable at succesively higher power levels. Currently around 10KW is about the tipping point, however Harris says they will compete up to 20KW with their newest product. Nautel weill surely follow, as will Continental. We should be anticipating a new group of transmitters shortly.
For clarification, I refer to FM systems. Transistor AM radios have been cost effective up to the 50KW power level for some time now.
There's is a considerable price difference at the 10 kw level.
I have three sites: One requires 2500 watts, one 3800 watts and one 8600 watts.
Was a no-brainer replacing a tube transmitter (2.5H) with a 2.5 kw Nautel for $18K. We just bought the second station with a 4 kw Energy-Onix, we have a new kilowatt BE box which will eventually be upgraded to a 5, which will cost around $20K.
Replacing the 10K is more problematical, even though it is 23 years old. Don't want another tube transmitter, but solid state boxes seem to start somewhere north of $40K.
Another consideration: Solid state transmitter manufacturers are gradually getting out of the lab and learning about the real world. Not all transmitter sites look like computer clean rooms with central, filtered air. Our Nautel was designed to pull in cooling air from two small openings on the side of the boxes (two 1400 watt amps and a combiner).
Did not work very well in hot weather even when mounted in an open sided rack. I had to knock a hole in a block wall and mount a window air conditioner to keep them happy. Their newer VS series pulls air in from the front panel. Bigger opening for better air circulation.
Our transmitter building at this site sits in a hay field. Hard to keep the critters out--found a mouse in my tool drawer the other day (well, he was building his own house...). When I have time I'll have to take the Nautels apart and blow the dust out.
BE's low power series was designed that way originally (air through the front for cooling), but they soon discovered that they had to add a snap-on filter to the front.
Our transmitter building for the 10K was built in '88. It has three fans pulling in filtered air from outside, three more (on thermostats) sending the hot air back out. The 10K is happy in this environment, even so, it gradually gets dirty from the fine dust, including coal dust that sneaks past the filters. Air conditioning this building would probably pull almost as much power as the transmitter...
The Energy Onix is in a concrete shelter with a companion 5 kw Harris HT (two different stations). The air conditioner runs even when it is in the low 30's outside. Ideal site for two solid state transmitters (two BE 5's could occupy the same space as the HT).
I have three sites: One requires 2500 watts, one 3800 watts and one 8600 watts.
Was a no-brainer replacing a tube transmitter (2.5H) with a 2.5 kw Nautel for $18K. We just bought the second station with a 4 kw Energy-Onix, we have a new kilowatt BE box which will eventually be upgraded to a 5, which will cost around $20K.
Replacing the 10K is more problematical, even though it is 23 years old. Don't want another tube transmitter, but solid state boxes seem to start somewhere north of $40K.
Another consideration: Solid state transmitter manufacturers are gradually getting out of the lab and learning about the real world. Not all transmitter sites look like computer clean rooms with central, filtered air. Our Nautel was designed to pull in cooling air from two small openings on the side of the boxes (two 1400 watt amps and a combiner).
Did not work very well in hot weather even when mounted in an open sided rack. I had to knock a hole in a block wall and mount a window air conditioner to keep them happy. Their newer VS series pulls air in from the front panel. Bigger opening for better air circulation.
Our transmitter building at this site sits in a hay field. Hard to keep the critters out--found a mouse in my tool drawer the other day (well, he was building his own house...). When I have time I'll have to take the Nautels apart and blow the dust out.
BE's low power series was designed that way originally (air through the front for cooling), but they soon discovered that they had to add a snap-on filter to the front.
Our transmitter building for the 10K was built in '88. It has three fans pulling in filtered air from outside, three more (on thermostats) sending the hot air back out. The 10K is happy in this environment, even so, it gradually gets dirty from the fine dust, including coal dust that sneaks past the filters. Air conditioning this building would probably pull almost as much power as the transmitter...
The Energy Onix is in a concrete shelter with a companion 5 kw Harris HT (two different stations). The air conditioner runs even when it is in the low 30's outside. Ideal site for two solid state transmitters (two BE 5's could occupy the same space as the HT).
A site in Indiana has used a tube box at 6 kw. Their IPA and exciter (on a hill with no farming nearby) have died numerous times related to dust and dirt. QEI 10k. Only 1 transmitter in the building. Retro replacement continues of a sheet protector on the back panel to thwart arc over.
Our site is in a farm field and while this is a dirty farming site (no till) the transmitter has stayed relatively clean. CCA 5K. Replaced the IPA w solid state. Translator using a PTek. It is difficult for it to stay clean. Filtered air conditio0ning air.
At many of our sites we are in churches. For translators. One site has a Gates 1. Nice transmitter after fix on the air sensor switch. 4 switches in a row at new install. I would hate to need support however. These are usually clean and air conditioned.
The cost of anything solid state is out of our ballpark except for 2500 w or less. We have used transmitters (tube) in the chain.
Our site is in a farm field and while this is a dirty farming site (no till) the transmitter has stayed relatively clean. CCA 5K. Replaced the IPA w solid state. Translator using a PTek. It is difficult for it to stay clean. Filtered air conditio0ning air.
At many of our sites we are in churches. For translators. One site has a Gates 1. Nice transmitter after fix on the air sensor switch. 4 switches in a row at new install. I would hate to need support however. These are usually clean and air conditioned.
The cost of anything solid state is out of our ballpark except for 2500 w or less. We have used transmitters (tube) in the chain.
Personal opinion here... In the year 2011 I think owners are a fool to consider a tube transmitter, especially any tube transmitter other than Continental. All of the other tube boxes are more trouble than their worth. With that being said, tube rebuilding is getting poor. That's a huge factor. My favorite SS box is either the Harris Z or ZX. Same modules... If I had to go high power, I'd bite the bullet and ask for a Nv30, NV40 etc from Nautel. With a good SS treated right they will generally keep you on the air at some power level even when something breaks, and the number of breaks are generally minimal. Don't let the manufactures BS you about power line efficiency. Being on the air reliably is job one. Don't create indigestion for yourself for the next 20 years. Keep a good SS grounded, cool, clean, and dry with a good power protector and you can worry about other things and almost forget you have a transmitter to goof with.
This one is worth fighting for with the owners. Initial costs might be much higher, but your overall costs including off-air issues will be much lower. You'll be happier with yourself in 10 years with a Harris or Nautel Solid State box.
On a side note, I know of a couple smaller market guys that bought a new HPX to replace their Z5s so they could do HD etc. They are still kicking themselves for doing it. One of them removed the z and has been off the air a LOT. The other has had better luck than the first, but has had some off air. They never bothered to hook up their old z which was a big mistake also. They are planning to do so soon though because they have been off for a day or so due to the HPX failing. Any tube box doesn't have real redunacy in them. If you have a backup and a full-time engineer, going SS might be less critical today. The real question of the week is if your replacement or assistant Eng can fix tube transmitters. I see less younger people being able to handle it. Again, in the year 2011 it's best to go SS.
Another vote for SS.
I work on 3 of the Harris Z10, 1 of the Nautel V10, a BE 2C and a BE 4C. The Nautel has been a nightmare (I won't go into that now), but the BE solid states have never hiccuped once. The Z10's have needed a couple of new modules. All in all, much cheaper and easier to maintain and more reliable than our tube transmitters.
I work on 3 of the Harris Z10, 1 of the Nautel V10, a BE 2C and a BE 4C. The Nautel has been a nightmare (I won't go into that now), but the BE solid states have never hiccuped once. The Z10's have needed a couple of new modules. All in all, much cheaper and easier to maintain and more reliable than our tube transmitters.
And one more for SS. I have a 13 year-old Z5 that has NEVER failed. Kudos to Harris on that one!
I have Z series sitting side by side with tube analog. We do about the same amount of maintenance on each. The tube boxes are substantially cheaper to fix when they do fail. The Z's usually need replcement cards at high dollars, since I don't have a surface mount rework statiion. Neither needs a lot of maintenance, they live in climate controlled shelters. We don't see a great difference in electric burn winter to summer, properly designed, the plant heat load will be whatever the transmitter sheds. The lack of failures due to dirt, bugs, critters, etc. more than offsets the extra power bill if your air time has any value. The city has bus exhaust - conductive - which preclusdes outside air use.
I find the comments on the HPX interesting. I looked at it and felt like they'd finally built one you could work on, with a couple of glaring exceptions. No more hidden fuses, or other such silly crap. There's still someone in Quincy whose Mama was scared by a solenoid though. I've lost airtime on an HT-HD from two causes - expired drive amps, and the g--dam shorting solenoid system. I've an HT in analog only though in standby service and it's the first Harris I've maintained which could be trusted to come on and run from cold. I've a handful of three bay Continentals though, which just sit there and run.
I find the comments on the HPX interesting. I looked at it and felt like they'd finally built one you could work on, with a couple of glaring exceptions. No more hidden fuses, or other such silly crap. There's still someone in Quincy whose Mama was scared by a solenoid though. I've lost airtime on an HT-HD from two causes - expired drive amps, and the g--dam shorting solenoid system. I've an HT in analog only though in standby service and it's the first Harris I've maintained which could be trusted to come on and run from cold. I've a handful of three bay Continentals though, which just sit there and run.
"I have a 13 year-old Z5 that has NEVER failed. Kudos to Harris on that one"
Me too! I have one that old and have NEVER fixed it. I've cleaned it, tightened it, but NEVER FIXED IT. How's that for reliable eh? It's a AMAZING box. Mine is a Z5. What a wonderful piece of art.
Me too! I have one that old and have NEVER fixed it. I've cleaned it, tightened it, but NEVER FIXED IT. How's that for reliable eh? It's a AMAZING box. Mine is a Z5. What a wonderful piece of art.
"I find the comments on the HPX interesting. I looked at it and felt like they'd finally built one you could work on, with a couple of glaring exceptions. No more hidden fuses, or other such silly crap." I'm impressed with the better design compared to a damn high-powered HT like the HT35CD. What a POS that thing is. With that being said, there seems to be a few issues with the new tube box also. Hopefully over time they'll work some of that stuff out. My favorite tube transmitter is still a Continental. Part of that too for people here in Okieland is parts ar about 2 hours away or less. It really makes it almost like having spares. Many station owners are too cheap to really have parts on the shelf, so this is a great option for those of us in this part of the country to get back on fairly quickly. "There's still someone in Quincy whose Mama was scared by a solenoid though. I've lost airtime on an HT-HD from two causes - expired drive amps, and the g--dam shorting solenoid system." Boy you've got that right. The damn shorting drop-ball goofy-assed system they designed is a total joke. Also, that contactor that requires freak'in oil is a real amazing deal. I've asked myself "who builds this s##t?!" so many times when working with that HT35CD. What a terrible excuse for a transmitter. How about that extra fun plate blocker? Yeah. Glad that's gone in the HPX! "I've an HT in analog only though in standby service and it's the first Harris I've maintained which could be trusted to come on and run from cold." I will say this. I have a HT5 that's been a real nice transmitter. I've only had to fix a power supply once for the IPA one time. Other than changing a tube once, it's just ran and ran. It's hard to believe it's the same series as the higher power HT stuff. The difference is night and day. "I've a handful of three bay Continentals though, which just sit there and run." Treated right, CE stuff is amazing when it comes to tube technolgy. A co-locate at one of my sites has a pair of nice high-powered Continentals. They just run. He's smart though. He has good air conditioning, a fairly clean room, and treats his stuff good, going to the tower regularly to check on it. He also has a very, very good LEA power protector hanging on the wall. Something tells me that protects his CE much better than most are treated. He also has a chemical ground for his tower. I worked for a major player here in OKC for over a decade on a pair of 20KW CEs that were reliable but did have their issues from time to time. Looking back on it, the lack of a very good power protection scheme cost us a lot of SCRs and a few caps over the years. It would have paid for us to ask for excellent protection in the years we were printing money. Oh well... The things a guy learns over the years. The past could sites I've built certainly has had a great protection put in from day one. Guess how many failures those sites have had so far? Pretty much none. 
We hang LEA boxes on the power feeds. They're worth it.
Pair in OKC? Lesse, KATT had a bare bones pair of Gen 4s into a six bay at one point, forget the Chief's name. And Dennis Orcutt had a pair as well at one point up at the tower/skunk farm, didn't he? He was feeding one side of a Dielectric combiner, and there was an early HT on the other side of it - I think it was the 'proof of concept' radio, Field Service from Quincy spent a LOT of time getting it to run reliably. I think they finally got it sorted out and going.
Pair in OKC? Lesse, KATT had a bare bones pair of Gen 4s into a six bay at one point, forget the Chief's name. And Dennis Orcutt had a pair as well at one point up at the tower/skunk farm, didn't he? He was feeding one side of a Dielectric combiner, and there was an early HT on the other side of it - I think it was the 'proof of concept' radio, Field Service from Quincy spent a LOT of time getting it to run reliably. I think they finally got it sorted out and going.
I believe the latter one you speak of is the old 98.9 KZBS (KLNK) now KYIS...
Tube HD transmitter effeciency reminds me of the specs of old AM high-level modulation transmitters.
40 to 60% overall effeciency with a 30 KW heat output of 60,000 to 75,000 btu!
40 to 60% overall effeciency with a 30 KW heat output of 60,000 to 75,000 btu!
At least old high-level modulation AM transmitters in nice condition are still loved by hams and museums. HD boxes, on the other hand . . .
Well, now I got to go look. I believe, however, the efficiency of the Z HD is about the same as the HT-HD. A linear system isn't gonna be as efficient as a Class C one, regardless the device which generates the waveform.
Someone - I believe maybe Jim Hanry - used to fire up the old 50 F at6 KRMG whenever there was a valid excuse to turn off the Ampliphase. It was a hoss, sounded like a dream. And dimmed all the lights in Munford on mod peaks.
Someone - I believe maybe Jim Hanry - used to fire up the old 50 F at6 KRMG whenever there was a valid excuse to turn off the Ampliphase. It was a hoss, sounded like a dream. And dimmed all the lights in Munford on mod peaks.
Yup! I don't know if it's still working, but I know they ran it in 2000.
The Public station put in a pair of Z12 HD's (combined). They need a lot more air flow than the BE FM10A they replaced.
Serial #00001 of the HT series sits up at Deer Point (not "mine").
After years of abuse and problems Harris sent someone out to do all the mods and make it work.
Abuse! How about a hole cut into the PA cavity with 1-7/8" line from the old RCA stuck in it. Why spend $$$ on a transfer switch. HT crashes? Hook the RCA up right here->
Serial #00001 of the HT series sits up at Deer Point (not "mine").
After years of abuse and problems Harris sent someone out to do all the mods and make it work.
Abuse! How about a hole cut into the PA cavity with 1-7/8" line from the old RCA stuck in it. Why spend $$$ on a transfer switch. HT crashes? Hook the RCA up right here->
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