looking for someone that can build a 3 or 4 3- 500z box pm me all info i would appreciate the help!!!!!!!someone that can be fully trusted and wont burn nobody thank for thye help
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looking for amp!!!!
- Thread starter excavator701
- Start date
Hmm. That guy probably wouldn't want to be advertising on the web. Yeah, I know some of them do, but they seem to fall into two categories.
First is the guy who'll apply commercial-grade engineering, with all the small filtering components, internal shielding and overload protection for both the tubes and the power supply. The sockets will have air flow BOTH on the underside of the sockets and on the glass topside. You wouldn't believe how many "expanded" SB-220 chassis I've seen with NO air on the undersides of the sockets. The factory-stock fan on that model blows BOTH on the topside and underside of the tubes. Don't think I've seen ONE modified SB-220 that did.
This guy will probably quote you between $5000 and $6000, and always gets underbid by the second category.
These outfits build "gutless wonder" boxes, in which a component gets left out UNLESS it contributes to making the wattmeter needle go farther. Parts that keep the tubes stable, parts that limit tube damage during a surge, parts that keep the signal reasonably clean, all get left out. That's how they underbid the first guy, by cutting corners they think the buyer won't know about. Not until the first set of tubes goes flat. Usually way too soon.
I gotta ask, why you want that many 3-500Z tubes. Sure, when there were made and sold by multiple sources they were very cost-effective compared to other, newer tube types. My problem is with using more than two of ANY tube. If you need four tubes, what you REALLY need is larger tubes, or one that will do the job alone.
I'll skip putting you to sleep with the added risks of using three or more tubes together. Just consider that with one tube, you have one chance of tube failure. A box with four tubes offers you FOUR places(chances) for that same failure to happen. Makes it four times as likely, all things being equal.
Consider also, that if one tube fails a year or more down the line, you can no longer just pop a NEW tube in with three older, tired tubes. Even if they still deliver 90 percent of what they did when new, the new tube will pull more than just one-fourth of the load. The parts of the load that the older tubes WON'T pull, will ALL get loaded onto the new (meaner) tube. As a result, it tends to pull more power than it can take, and fails far too soon. UNLESS you watch that one, and throttle down below the danger point. Throttling down is almost never what a guy with four 3-500Z tubes will do voluntarily.
If you have to replace all four tubes just because one (only) failed, the upkeep price of this thing gets a lot higher. A box with one or two tubes will never need more than that to put it back on the air.
Too bad Henry Radio no longer makes their "5k Classic" model. It used two 3CX1200 tubes. Each of them is a little larger than one pair of 3-500Z. Requires LESS drive, to boot. And that tube is one of the stoutest that Eimac ever built. Worth considering if you plan to run AM. AM is just hard on an amplifier if it was designed with SSB in mind, like all commercial ham linears tend to be.
I should put up some pics of poorly-engineered "big" tube boxes we've seen. Some of them are pretty hilarious, so long as none of your money got tied up in one of them.
73
First is the guy who'll apply commercial-grade engineering, with all the small filtering components, internal shielding and overload protection for both the tubes and the power supply. The sockets will have air flow BOTH on the underside of the sockets and on the glass topside. You wouldn't believe how many "expanded" SB-220 chassis I've seen with NO air on the undersides of the sockets. The factory-stock fan on that model blows BOTH on the topside and underside of the tubes. Don't think I've seen ONE modified SB-220 that did.
This guy will probably quote you between $5000 and $6000, and always gets underbid by the second category.
These outfits build "gutless wonder" boxes, in which a component gets left out UNLESS it contributes to making the wattmeter needle go farther. Parts that keep the tubes stable, parts that limit tube damage during a surge, parts that keep the signal reasonably clean, all get left out. That's how they underbid the first guy, by cutting corners they think the buyer won't know about. Not until the first set of tubes goes flat. Usually way too soon.
I gotta ask, why you want that many 3-500Z tubes. Sure, when there were made and sold by multiple sources they were very cost-effective compared to other, newer tube types. My problem is with using more than two of ANY tube. If you need four tubes, what you REALLY need is larger tubes, or one that will do the job alone.
I'll skip putting you to sleep with the added risks of using three or more tubes together. Just consider that with one tube, you have one chance of tube failure. A box with four tubes offers you FOUR places(chances) for that same failure to happen. Makes it four times as likely, all things being equal.
Consider also, that if one tube fails a year or more down the line, you can no longer just pop a NEW tube in with three older, tired tubes. Even if they still deliver 90 percent of what they did when new, the new tube will pull more than just one-fourth of the load. The parts of the load that the older tubes WON'T pull, will ALL get loaded onto the new (meaner) tube. As a result, it tends to pull more power than it can take, and fails far too soon. UNLESS you watch that one, and throttle down below the danger point. Throttling down is almost never what a guy with four 3-500Z tubes will do voluntarily.
If you have to replace all four tubes just because one (only) failed, the upkeep price of this thing gets a lot higher. A box with one or two tubes will never need more than that to put it back on the air.
Too bad Henry Radio no longer makes their "5k Classic" model. It used two 3CX1200 tubes. Each of them is a little larger than one pair of 3-500Z. Requires LESS drive, to boot. And that tube is one of the stoutest that Eimac ever built. Worth considering if you plan to run AM. AM is just hard on an amplifier if it was designed with SSB in mind, like all commercial ham linears tend to be.
I should put up some pics of poorly-engineered "big" tube boxes we've seen. Some of them are pretty hilarious, so long as none of your money got tied up in one of them.
73
I encourage you to do that Chris, so the guys here can look at them and know what to look for in a custom built Amp, before plunking down there hard earned monies on a "three mile island" Box.
73
Jeff
5tuber and 8tuber
you should hear the guy in colorado talking on his 5 tube
3-500z driver
and you should hear the guy coming out of texas running the 8tuber with 500zg
sometime check out the 5tuber in the back of the burb
and to be right down with it
a guy brought his 5tuber in to be worked on relay burnt out and wanted to retube the amp with 500zg
it was built back in 87
you should hear the guy in colorado talking on his 5 tube
3-500z driver
and you should hear the guy coming out of texas running the 8tuber with 500zg
sometime check out the 5tuber in the back of the burb
and to be right down with it
a guy brought his 5tuber in to be worked on relay burnt out and wanted to retube the amp with 500zg
it was built back in 87
Hello Nomadradio:
If you ever write a book, put me first on the list. Trurer words have not been spoken! Please do post the cheap amplifiers photos.
After hearing many many stories about large amps not working right, and simply catching fire. Your posting is dead nuts on.
Not to mention that the amplifiers that use tubes have lethal voltages that can kill you in a New York second!
I have quit a few questions from Interceptor 10K Antenna users about high power and such. One customer using a 6 meter Interceptor 10K had his amplifier catch fire and the radio and antenna wasn't even hooked up yet.
There is a need for a amp buyers check list for things to look for before laying down several thousand dollars, for junk! I hear many stories of guys putting down half the money and never seeing anything aftrer that. Not good.
One thing I have noticed on some cheap amplifiers is that they don't have all the meters needed to indicated whats going on in the amplifier. I want to see the Plate Voltage and Current and grid current. Also the output power.
Jay in the Mojave
If you ever write a book, put me first on the list. Trurer words have not been spoken! Please do post the cheap amplifiers photos.
After hearing many many stories about large amps not working right, and simply catching fire. Your posting is dead nuts on.
Not to mention that the amplifiers that use tubes have lethal voltages that can kill you in a New York second!
I have quit a few questions from Interceptor 10K Antenna users about high power and such. One customer using a 6 meter Interceptor 10K had his amplifier catch fire and the radio and antenna wasn't even hooked up yet.
There is a need for a amp buyers check list for things to look for before laying down several thousand dollars, for junk! I hear many stories of guys putting down half the money and never seeing anything aftrer that. Not good.
One thing I have noticed on some cheap amplifiers is that they don't have all the meters needed to indicated whats going on in the amplifier. I want to see the Plate Voltage and Current and grid current. Also the output power.
Jay in the Mojave
nomadradio said:
The following is NOT intended for the CB retards.....(this is not a knock on CB, its a knock on the retards who operate CB! Not everyone who operates CB is a retard. Those who are, know who you are!)
http://www.somis.org/perfect_amp.html
http://www.somis.org/perfect_amp.html
amplifier
im just looking for someone that can build something in the 2500 to 3500 range leave me a private message or email me @nissanman514@yahoo.com leave info and prices it deosnt have to be 3500z either just let me know what you can do thanks!!!!!
im just looking for someone that can build something in the 2500 to 3500 range leave me a private message or email me @nissanman514@yahoo.com leave info and prices it deosnt have to be 3500z either just let me know what you can do thanks!!!!!
is there any particular reason you want one built for you? i have a very nice Drake L4-B. it uses (2) 3-500z's and puts out right around 3500 watts when driven with a sb200 heathkit. they are both 4 sale in the sale section listed under 12 pill dave made 4 sale. are you the same excavator that lives in NC? $800 for the drake and $400 for the heathkit, $1100 for both... what a deal... L8ter
Hey Excavator,
Consider that your description calls for roughly double what most factory-made 'ham' amplifiers can deliver without premature failure of expensive pars. I'd recommend settling for around 2000 Watts peak. That Drake will run at this level quite comfortably. And the difference on the receiver S-meter at the FAR end of the conversation is less than one-half an S-unit, dropping from 3000 to 2000. Drop from 4000 to 2000, and you'll make roughly one-half of a number's difference. The guy at the other end can't see your wattmeter.
Widespread availabilty of ham amplifiers that will run at this level makes them cheaper per Watt than a custom-made, every time. Just ask your favorite mechanic to build you a car, and compare his labor bill to the price of the same car made on an assembly line. Just costs more that way.
For that matter, an Ameritron AL-1200 is still under $3000, last I looked. Won't break a sweat at 2000 Watt peaks. Around 3000 you're hot-rodding, and weak points in the design will start to show. Same goes for the Drake L-4 models. Yes, they'll scream past 3000 if you drive the pants off them, but so many parts last so much longer at 2000 or less, it's hard to justify the cost of a half S-unit (or less) for the extra wear and tear.
Just stay away from the AL-1500. It's a fine amp, and holds up to normal SSB use. But on AM, you'll break it sooner than the 1200. Power from each model is essentially identical. The 3CX1200 tube is LOTS tougher under abuse than the 3CX1500/8877 tube used in the AL-1500.
73
Consider that your description calls for roughly double what most factory-made 'ham' amplifiers can deliver without premature failure of expensive pars. I'd recommend settling for around 2000 Watts peak. That Drake will run at this level quite comfortably. And the difference on the receiver S-meter at the FAR end of the conversation is less than one-half an S-unit, dropping from 3000 to 2000. Drop from 4000 to 2000, and you'll make roughly one-half of a number's difference. The guy at the other end can't see your wattmeter.
Widespread availabilty of ham amplifiers that will run at this level makes them cheaper per Watt than a custom-made, every time. Just ask your favorite mechanic to build you a car, and compare his labor bill to the price of the same car made on an assembly line. Just costs more that way.
For that matter, an Ameritron AL-1200 is still under $3000, last I looked. Won't break a sweat at 2000 Watt peaks. Around 3000 you're hot-rodding, and weak points in the design will start to show. Same goes for the Drake L-4 models. Yes, they'll scream past 3000 if you drive the pants off them, but so many parts last so much longer at 2000 or less, it's hard to justify the cost of a half S-unit (or less) for the extra wear and tear.
Just stay away from the AL-1500. It's a fine amp, and holds up to normal SSB use. But on AM, you'll break it sooner than the 1200. Power from each model is essentially identical. The 3CX1200 tube is LOTS tougher under abuse than the 3CX1500/8877 tube used in the AL-1500.
73
Redbone west of Atlanta can do it. PM me if interested and I'll give you his phone number. He is expensive but can build anything.
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