Icom PW-1

[NZ9Y]

I have an opportunity to buy a PW-1 for not much more than a used high quality tube amp (Alpha, etc). Even at that its still expensive. It will require me to do about a 16 hour drive to pick it up and the guy will have it already uninstalled so I wont have a chance to test drive it.

Here's the kind of experience I've had buying used stuff from hams in the last 4 months:

FT-101E claimed unmolested by seller, was totally hacked and pretty much ONLY usable on 11m AM. I paid top dollar for piece of mind, then paid again to make it actually work (thanks Carol!)

IC-756Pro2 that drew 2 amps current WHEN TURNED OFF! Expensive fix.

Tailtwister rotor that was actually a Ham2.

Now I have gotten items from hams that were as advertised, but probably less than 50% of the time. I'm nervous on this one. The deal is good, and the drive will be brutal.

I really like the idea of a fully automatic amp setup. Alot of the DX I work is "sniping" stations I find on the cluster. I also have a fairly complete FT101E/FL2100B station to fullfill my occasional need to tune up for 10 minutes everytime I change frequency. I like both, modern automation and vintage manual tuning.

So my question is this, if I use this amp with only recent mfr Icom rigs (7600, Pro2) and follow all the connection and setup info carefully, is it likely to be trouble free? I've never hurt an amp yet, should I be OK with the solid state stuff?

Are these high power SS amps (Icom, Yaesu) fairly reliable? I know the Ameritron version gets some bad press on eham.

[WB2WIK]

After a 16 hour drive, I'd insist on a demonstration of the amp actually working. "Uninstalled?" The PW-1 only requires two cables be plugged in to "re-install" it. It doesn't weigh much. If the seller has no transceiver or antenna to connect it to, I'd bring along a rig and a big dummy load.

No way I'd make such a trip to buy anything I can't see working.

[W4PG]

I have a PW-1 and they are very nice. However, you do have to adjust the ALC with any new setup so you don't blow the thing up. I say that only 'cuz if you plan on taking a rig along to hook it up, you'll need to do that to fully test it out. It also has a built in antenna tuner . . . . you need to make sure that is working also.

My only gripe is the amp is 1000 watts and not 1500 out. Yea, only 3 db, but . . . . :-)

................Bob

[WB2WIK]

I have a PW-1 and they are very nice. However, you do have to adjust the ALC with any new setup so you don't blow the thing up. I say that only 'cuz if you plan on taking a rig along to hook it up, you'll need to do that to fully test it out. It also has a built in antenna tuner . . . . you need to make sure that is working also.

My only gripe is the amp is 1000 watts and not 1500 out. Yea, only 3 db, but . . . . :-)

................Bob

"New math," Bob?

It's 1.76 dB.

Interesting point about the ALC, though. I don't have a PW-1. What if you use it with a rig that has no ALC input at all, like every Ten Tec rig? I'd think you could just leave the ALC disconnected and adjust the rig's drive down to whatever it needs to be...?

[KB1NXE]

You would be able to get by without adjusting the ALC as long as you DO NOT exceed the 1KW limit. Start with the RF Output turned down and then turn up to the 1KW limit.

I do have a PW-1. They are great amps as long as you do not exceed their designed specs. But that's true of a lot of things. I agree if you are unable to test it, then the risk is [to me] unacceptable. Uninstalling a PW-1 is minor work. Power, Input, Output, Keying and ALC. And at that, the ALC is optional. Not much different (to test) than a standard amp. The controls are all right there.

Also, be aware there are two versions of the PW-1. Google it.

[W4PG]

"New math," Bob?

It's 1.76 dB.

Negative. The correct value is 1.760912591. :-)

Interesting point about the ALC, though. I don't have a PW-1. What if you use it with a rig that has no ALC input at all, like every Ten Tec rig? I'd think you could just leave the ALC disconnected and adjust the rig's drive down to whatever it needs to be...?

I think you are correct. The nice thing about hooking up the ALC from my PW-1 to the 7800 is if I forget to drop the power on the 7800, the ALC connection automatically does it for me. Otherwise, one just has to make sure they don't overdrive the PW-1 with what-ever exciter they are using! No biggie unless you forget . . .

...............Bob

[N0AZZ]

Negative. The correct value is 1.760912591. :-)

I think you are correct. The nice thing about hooking up the ALC from my PW-1 to the 7800 is if I forget to drop the power on the 7800, the ALC connection automatically does it for me. Otherwise, one just has to make sure they don't overdrive the PW-1 with what-ever exciter they are using! No biggie unless you forget . . .

...............Bob

Yes I know what you mean I do the same thing with my Yaesu FT-5000 and a VL-1000 good deal if someone has twisted the knob up to 200w.

[NZ9Y]

I wish I had waited for some replies to this thread before I made the trip to Chicago. Sorry this is long.

A few hours after I started this thread, the available time suddenly came up. I hopped in the car, threw in a hamstick and 756Pro2 to keep me company and started.

I got there about 7 hours later. The amp was all pulled out of the station and "ready" to go. The fellow seemed a decent sort. I paid my hard earned cash, loaded it into the car and started home.

After already driving 7 hours, I took it a little easier on the way home. 16 hours after I left, I rolled in about 2 AM. I was too tired to unload it.

Next morning, I carry the amp to my shack and set it on the table. I removed the 220v plug. It was melted.
The bare wires looked OK so I installed a new 120v plug. I did not plug it in. I connected the rig to input 1, the CIV line and the ACC line being VERY careful to connect it to the right ACC on the transciever. I set the ALC for max inhibit (CCW) and turned the rigs RF gain all the way down. Oil can 3kW dummy load on antenna 1 is the only antenna connected.

Now I connect the AC. Turn the power on, switch to antenna 1, input 1. I again verify the ALC is CCW for full inhibit and the RF if all the way down on the rig. The "amp" switch is still off. I hit the RTTY button and transmit. I can see the meter on the amp slightly twitch from the 2-3 watts in. I bump up the RF to about 10 watts and transmit again. More meter. Good.

The manual says now to turn the exciter RF to 100 watts then adjust the alc to full output on the amp. This way even if you forget to turn your exciter down, you can never overdrive the amp. I'm more cautious than that and leave the exciter at 10 watts which should be more than enough for a quick test.



Now I turn the "amp" on. Remember the ALC is at full inhibit. I key the exciter. The amps power meter runs up to maybe 200 watts out, SWR is perfect of course. I've been transmitting maybe 10 seconds and suddenly BZZZZZZZZZZT!!! Ozone and terror!

It was still arcing when I hit the power button. It was still arcing as I climbed under the desk to unplug it. It did stop before I got to the plug.

I called Matt at Icom. He verified I had all connected correctly. Amazingly he said he would stay on the phone while I ran a quick diagnostic for him. He had me unplug the ACC and CIV and connect up an RCA to the send. "No ALC?" "Right, its only a safety net and really not needed except to protect the amp from mistakes."

I plugged it into the wall. No fireworks. I turned on the power and it powered up. Witht he exciter RF all the way down, I keyed up and got 50 watts out, normal according to Matt. I SLOOOWLY started to turn the RF up. At about 200 watts the amp faulted and shut down. Tried again and the same.


I'm done buying used. If I can't afford it new with a warranty, I'll do without. The seller assures me it was fine when it left. They all say that, yet somehow I have NEVER, EVER gotten a used electronic item from another ham that worked. Yet, I've bought tons of used stuff from my local ham store and never had an issue, including 2 other amps.

The seller tells me he will pay for repairs or return my money. Luck (or chance, destiny) happens, both good and bad. If he really does come through, I will hold him in high esteem and publicly recommend him.

Sigh.

[K9FV]

Bummer on the amp - those are good amps from all I've read. Hopefully the seller will come thru on his promises.

I removed the 220v plug. It was melted

That might have been a clue?

Good luck with the repairs,

73 de Ken H>

[K9FV]

Ooops - double post.