Ameritron AL-811 or ?

#341264

Looking to get my first tube amp to drive with some older radios: colt midnite special, sonar fs 2340, dak 10 and tram titan 2. These radios probably don't have enough to drive the AL-811? I've been told to stay away from sweep tube amps as they're junkie splatter boxes and hard to find expensive tubes. Soft start would be nice. Would like a high and low power setting, like 100 Low and High 500- 1000 settings. What would be a good tube amp for this? Thanks

#341391

Well,I can tell you this much. I have an Ameriton AL-82 (Two 3-500G's tubes) and 12 watt drive will give me 400 watts out. That is plenty on SSB.

#341393

That's over 15dB. The only triode I know of capable of that is a 3cpx5000.

#341394

galaxy95Tman wrote:Looking to get my first tube amp to drive with some older radios: colt midnite special, sonar fs 2340, dak 10 and tram titan 2. These radios probably don't have enough to drive the AL-811? I've been told to stay away from sweep tube amps as they're junkie splatter boxes and hard to find expensive tubes. Soft start would be nice. Would like a high and low power setting, like 100 Low and High 500- 1000 settings. What would be a good tube amp for this? Thanks

i dont know who told you tube amps are "junkie splatter boxes" but thats a load of mis information, i have tube amps and not only are they cleaner than my fatboy 5 pill as far as splatter, they sound 100 times better. if you want to splatter all over the band buy a transistor box, if you want a clean signal buy a tube amp and learn how to run it correctly.

As far as tubes being expensive, yes certain tubes can be pricey, however, again, if you run it correctly tubes can last many years.

Ill take my tube amps over my fatboy 5 pill base box any day of the week.

#341399

dirtyjob wrote:
galaxy95Tman wrote:Looking to get my first tube amp to drive with some older radios: colt midnite special, sonar fs 2340, dak 10 and tram titan 2. These radios probably don't have enough to drive the AL-811? I've been told to stay away from sweep tube amps as they're junkie splatter boxes and hard to find expensive tubes. Soft start would be nice. Would like a high and low power setting, like 100 Low and High 500- 1000 settings. What would be a good tube amp for this? Thanks
Key word being "SWEEP" tube amps, referring to the splatter. Thanks for all the reply's and imput guys!!

i dont know who told you tube amps are "junkie splatter boxes" but thats a load of mis information, i have tube amps and not only are they cleaner than my fatboy 5 pill as far as splatter, they sound 100 times better. if you want to splatter all over the band buy a transistor box, if you want a clean signal buy a tube amp and learn how to run it correctly.

As far as tubes being expensive, yes certain tubes can be pricey, however, again, if you run it correctly tubes can last many years.

Ill take my tube amps over my fatboy 5 pill base box any day of the week.

Sunday, 26 May 2013, 21:13 PM

De_Wildfire wrote:Well,I can tell you this much. I have an Ameriton AL-82 (Two 3-500G's tubes) and 12 watt drive will give me 400 watts out. That is plenty on SSB.

Those are cool looking (3-500GZ) tubes, but not $180 a piece cool!!

'Doc · #341408

If I were going to recommend an amplifier I would suggest using one that used tubes meant for transmitting/power amplification, not adapted from some other purpose. That pretty well rules out the 'sweep-tube' amplifiers. They do work, but the tubes are being 'pushed well beyond their intended ratings. The primary reason for using 'sweep tubes' is that they are (*were*) cheaper than those made for power amplification and that they are readily available. Since the use of these tubes is now not very prevalent at all, they don't really fit that 'cheap/plentiful' qualification.
The key to using any tube type amplifier is to operate the tubes in the most efficient manner possible. That means that they should be operated in a manner that get's the most efficiency out of them. That means that you don't 'de-tune' the amplifier to reduce power, you regulate the input dive to that amplifier to increase/reduce the output. The amplifier it's self is run in a maximum efficiency state, you keep the thing tuned! A tube manufacturer will give specifications for the maximum efficient use of a tube. That set of specs also is aimed at the maximum usable life span of that tube which means that it isn't doing the absolute max that it's possible to squeeze out of it. There's always a slight 'fudge factor' in that, but that almost always directly affects the life span of the tube. If you want more than is reasonably possible to expect from a particular tube, it's time to select a 'bigger' tube, not work that 'smaller' one to death. That's just not very hard to understand, is it?
It all boils down to how much you thing a watt is worth...
- 'Doc

#341428

That all makes perfect sense doc, thanks for that! What I'm wondering is if there is a tube amp out there with transmitting tube(s), NOT SWEEP TUBES,that will work well with only 4 watts dead key drive?? Maybe something where you could run 1 572B for low and two 572B's for high? Thanks

#341436

galaxy95Tman wrote:That all makes perfect sense doc, thanks for that! What I'm wondering is if there is a tube amp out there with transmitting tube(s), NOT SWEEP TUBES,that will work well with only 4 watts dead key drive?? Maybe something where you could run 1 572B for low and two 572B's for high? Thanks

Just look for amplifiers made for QRP transmitters

#341441

galaxy95Tman wrote: What I'm wondering is if there is a tube amp out there with transmitting tube(s), NOT SWEEP TUBES,that will work well with only 4 watts dead key drive??

Sure the amp will work well with 4 watts drive but your not going to 500-600 watts out of it.

galaxy95Tman wrote: Maybe something where you could run 1 572B for low and two 572B's for high?

There isn't any ham amplifier I know of that's made to operate like that and they all like around 100 watts drive.

I had a Heathkit DX-60 transmitter that I drove a SB-200 with that had a pair of 572B's at 10 watts drive I got around 100 watts out of the amp.

What your going to need is smaller amplifier to drive it with or get a radio that can provide the amount drive that's needed.

#341450

For AM mode I use a Cobra 29 radio into a Texas Star Mod V 1 pill amp, to drive my Ameritron AL-1500.
The stock Cobra is 4w, the TS Mod V is variable, with 60w out of it, I get full output from my Ameritron.
Another issue is how are you are going to "key" the Ameritron? They do not use an RF sensing circuit, a foot switch is one possibility, that's what I use.
Good luck and enjoy.

#341469

Thanks Night Crawler for clearing that up! Now I have the full picture! Thanks Hacksaw for sharing how your set-up is ran! Is 4 watts drive kinda high for a 1 pill or no?

#341471

721HACKSAW wrote:Another issue is how are you are going to "key" the Ameritron? They do not use an RF sensing circuit, a foot switch is one possibility, that's what I use.

That's not a problem make your own rf switching circuit it's just a transistor, a couple of diodes and a resistor or two or you could make a relay box that keys the radio and the amplifier.
A foot switch is a crude way to do it.

#341503

You can buy a foot switch with two sets of contacts. One for the radio and one for the amp. Think heil sells one and it won't break the bank.

#341505

I should have explained more, I use the ARB-704 interface between my HF rig and amp, I also have the foot switch connected to the ARB-704 interface for when I'm using my Cobra CB radio.
Two separate radios, both interfaced with the Ameritron amp...

#341859

RM Italy has the KLV1000 in a low drive. Uses the EL509 tubes which are rugged and the soviet replacements which work fine are cheap.

#341871

bluemeanie wrote:RM Italy has the KLV1000 in a low drive. Uses the EL509 tubes which are rugged and the soviet replacements which work fine are cheap.

That would be a great choice for his purposes and there's nothing wrong with sweep tubes if you run them within their ratings.
Actually there was an article in a 1969 QST magazine article showing how to homebrew your own amp using four 6KD6's which are almost as rugged (but not quite) as the russian tubes.

#341875

Thanks Bluemeanie and Night Crawler I'm going to look at that one for sure!!

#341876

bluemeanie wrote:RM Italy has the KLV1000 in a low drive. Uses the EL509 tubes which are rugged and the soviet replacements which work fine are cheap.

You can check it out on DNJ's site, look at the "P" model, cheaper and comes with a preamp, (hence the "P").

3's

Greg

#341908

Yes the KLV 1000 is a good option also, both models have the receive pre-amp.
I have a low drive that I bought from a member here. When my needs changed due to a radio change I had my local tech remove the driver tube and mod it for high drive. With 4 Svetlana 6P45s tubes and 65w drive it cruises at 500w output. The Svetlana tubes can still be found fairly cheap.
It's only a single band amp and not near the build quality of an Ameritron but no additional keying mods are needed either.

#341927

I watched a video on youtube about the KLV 1000 and he was having trouble with it using sideband, making weird noises. The comment below another guy said he had trouble with his too, bad solder joints. I would be using it on sideband mostly. Have you had any trouble with yours on sideband hacksaw? Thanks

#341933

For the same money as a KLV1000, you can buy a small driver and a SB220 and have a whole heck of a lot more amp.

#341935

No trouble with mine at all, I did replace the Svetlana tubes, they were weak when I got it.
Any amp only amplifies what you put into it, especially on SSB, if your radios signal and audio aren't clean or off freq an amp is just going to magnify the problem.
There is no perfect setup in radio, everything has a downside. I will say though your antenna is the most important part of any setup. I've had many radios and amps over the years, always with a ground plane type of antenna. I put up a beam a few years ago and it made more difference than any amp.

#341953

Does that KLV 1000 have a soft start or is that not needed for the low drive requirements?

#341961

There's no "Soft Start" on an RM Italy product, as posted above, it isn't the quality of an HF amp like an Ameritron.

#341966

I have a JUMBO amp which I am told is a RM Italy KLV 400 in a different box. It has two EL509 in it. I put a set of soviet tubes in it because I wanted a set of spares and wanted to make sure it they work. I bought the amp used, my radio drives about 3.5 on AM and around 12 pep on my high quality rat shack meter. The little amp runs about 275 out on SSb. AS I have no local traffic every time I turn my radio the box comes on too. For several years now it has never missed a lick and I get great signal reports everyday. Never has missed a beat. Garbage in garbage out. i have one of those nasty sweep tube boxes too. It was purchased as a collector piece as much as anything. Has 6 20lf6 in it which is a small fortune in tubes. But it does not splatter and get great reports from it as well. Not practical for everyday use. But cool for Sunday go to meeting.

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