200 Watt Amplifiers

[blindfire]

Anyone know if there is such a thing?

I was wanting to boost power on my home station. I already have a 200 W antenna tuner and was wanting to stay in that range.

I don't really want to lay out $600 for a 500W amp and then have to buy a 500W capable tuner.

I will if I have to...but not my first choice.

Thanks

 

[Finalygotabeltfed]

For what bands? There used to be several companies that made VHF and UHF amplifiers in the power range.+-

For HF, 500w and up is pretty much standard. Its the first 500w that will give the most advantage, from there you have to double the power for each S unit difference on the received end.

 

[drgrant]

For HF 200 vs 100 is a waste of time. You will want to try to get into the 400+ class on HF to see any real gains. If we're talking base ops here you might as well just get a 1-2KW capable tuner and start getting glass or tetrodes with handles...

-Mike

 

[blindfire]

Mike, thanks.

I am looking for HF 80 - 10.

If I go to a 500W amp, is the output adjustable up to 500W or is it just 500W? Like I said, I'd like to do an incremental type upgrade if at all possible.

Thanks

 

[uncle griz]

The gain from 100 to 200 watts is 3db. There is 6db per "S" unit, so you might see 1/2 of 1 S unit....not noticeable on the receive end......100 watts to 400 watts would be 6db, or about 1 "S" unit.....100 watts to 800 watts would be 9db, or about 1 1/2 "S" units........AB1CQ

 

[blindfire]

The gain from 100 to 200 watts is 3db. There is 6db per "S" unit, so you might see 1/2 of 1 S unit....not noticeable on the receive end......100 watts to 400 watts would be 6db, or about 1 "S" unit.....100 watts to 800 watts would be 9db, or about 1 1/2 "S" units........AB1CQ

Yeah, the math makes sense, but sadly, I will have to do the upgrade incrementally. I can see going to 600 W. So, maybe an Ameritron amp and an MFJ tuner.

 

[drgrant]

Mike, thanks.

I am looking for HF 80 - 10.

If I go to a 500W amp, is the output adjustable up to 500W or is it just 500W? Like I said, I'd like to do an incremental type upgrade if at all possible.

Thanks

Depends on how much you drive the thing, really, and how the ALC is set up (if applicable). The thing is, I will bet that 9 out of 10 times when you turn it on you're going to run it at 400 or more anyways.

-Mike

 

[drgrant]

The gain from 100 to 200 watts is 3db. There is 6db per "S" unit, so you might see 1/2 of 1 S unit....not noticeable on the receive end......100 watts to 400 watts would be 6db, or about 1 "S" unit.....100 watts to 800 watts would be 9db, or about 1 1/2 "S" units........AB1CQ

I bet its more than that on most S meters, though... but hams to explain it this way to try to convince people not to get an amp... but going from 100 to 800 is pretty significant (and audible) difference. Particularly on a band like 80M with the static crashes etc. The 100W stations are usually fighting in the weeds (but still audible) and the ones that are easy to listen to are typically running 400+.

-Mike

 

[drgrant]

Yeah, the math makes sense, but sadly, I will have to do the upgrade incrementally. I can see going to 600 W. So, maybe an Ameritron amp and an MFJ tuner.

The palstar tuners are way better than MFJunks, but a 989C will work OK if you can pick one up on the cheap and you ground it well.

The only ameritron experience I had was with an AL80B. If you get one of those things, try to find someone to help you mod it to make the bias "always on when keyed" because the automatic bias circuit in the thing sucks and creates tons of splatter/chop in the signal. After I had my amp tech mod it, one of the things I liked about it was it was pretty quiet in operation, and the 3-500ZG tubes are pretty durable.

Sadly, I wish I could remember what he did to the thing but the mod took him like 5 minutes, I think he removed a leg of a transistor or something trivial like that so the bias sensor would just think there was always enough input signal. It makes the amp run -slightly- hotter but its not even worth worrying about, I don't even know why the **** MFJ put it in the design to begin with....

FWIW there is a yahoo group called AMPS that's an email list, if its still around I would subscribe to it. BTW the smartest guy on there is Rich Measures, by orders of magnitude. He has a wacky sense of humor but he knows more about tube amps than most people have forgotten.

ETA: If you pick up a DC based amp and you need a stupidly large power supply to run it, I have a PowerTen rackmount supply in my basement you could borrow indefinitely... I am pretty sure it still works but I'd have to test it. 220 vac input, though.. but does 0-20 VDC out at 100A. All I know is it cost somebody like 3 grand back in 2000? or so...

-Mike

 

[cockpitbob]

One more reason to not get a 200W amp is I wouldn't put 200W into a 200w tuner. Especially if it's an MFJ VersaTuner.

 

[blindfire]

One more reason to not get a 200W amp is I wouldn't put 200W into a 200w tuner. Especially if it's an MFJ VersaTuner.

Gotcha...my tuner is LDG...but the point is taken.

Do most amps have decent reflection rejection like most radios do? In other words, if my SWR is under 4:1, will the amp still work? Or is this why the amp should be behind the tuner relative to the antenna?

 

[Orion2k]

I don't think 4:1 will play well with any amp. I can't speak for tube amps because I don't have one but for the solid state amps they have protection circuits to shut down the amp if it detects a high SWR. I originally had a Yaesu FL-700 for 16 years that would trip like crazy on 1.5:1 until I had it modified by N4ATS. I've since switched to a Quadra VL-1000 and don't have a problem up to 2:1 but beyond that it trips. My MFJ989 is a 3kw tuner and it sees the antennas before the amp but I haven't had to use it since I bought the Quadra so it just sits in direct mode. Check out Bill's website N4ATS.com he has some nice information.

If all you want to run is 200 watts then why not look into a 200 watt radio like the Yaesu FT2000D or the older FT1000MP MK5 (Not the field version). I'm sure there may be others that run 200 max right out of the radio I just happen to be a Yeasu guy.

 

[blindfire]

I don't think 4:1 will play well with any amp. I can't speak for tube amps because I don't have one but for the solid state amps they have protection circuits to shut down the amp if it detects a high SWR. I originally had a Yaesu FL-700 for 16 years that would trip like crazy on 1.5:1 until I had it modified by N4ATS. I've since switched to a Quadra VL-1000 and don't have a problem up to 2:1 but beyond that it trips. My MFJ989 is a 3kw tuner and it sees the antennas before the amp but I haven't had to use it since I bought the Quadra so it just sits in direct mode. Check out Bill's website N4ATS.com he has some nice information.

If all you want to run is 200 watts then why not look into a 200 watt radio like the Yaesu FT2000D or the older FT1000MP MK5 (Not the field version). I'm sure there may be others that run 200 max right out of the radio I just happen to be a Yeasu guy.

Well, crap! Why didn't I think of that? I may consider that. I'm taking a trip up to the Candy Store on Saturday. Will look at both options.

Does HRO have a store credit card?

 

[timbo]

Another thing you might consider is, if you can have one, is put up a tower and a triband beam...used towers in good condition can be had quite reasonably and a tribander up around 30-40 feet will give you much more apparent power than an amp, plus it also works in reverse... whatever the db gain in the transmit signal is also will give you that on receive as well. Just something to think about.

I used to have a tower about ten years ago and I sure miss what it could do for me. The center fed zepp works ok on the lower bands but the difference between a wire antenna and a yagi is amazing on the upper HF bands (20-10 meters). I am hoping to get a tower back up before the snow flies this winter.

 

[cockpitbob]

Another thing you might consider is, if you can have one, is put up a tower and a triband beam...used towers in good condition can be had quite reasonably and a tribander up around 30-40 feet will give you much more apparent power than an amp, plus it also works in reverse... whatever the db gain in the transmit signal is also will give you that on receive as well. Just something to think about.

I used to have a tower about ten years ago and I sure miss what it could do for me. The center fed zepp works ok on the lower bands but the difference between a wire antenna and a yagi is amazing on the upper HF bands (20-10 meters). I am hoping to get a tower back up before the snow flies this winter.

Yup, Yagi's are great. On Rx not only do they have "gain" but they ignore all the noise they aren't pointed at.

Timbo, a question. With a really bad solar minimum coming up (seems like it's already here many days) is a tower for a beam that won't work bands below 20 useful? Ive only been licensed since 2010 so I haven't lived through a bad solar minimum. Presently I see a lot of days where 20m is the shortest band that will cross the Atlantic. Do you think things will get bad enough that even 20m is above the max usable frequency?