Ameritron ALS-600

[W3XAF]

I recently purchased a solid-state Ameritron ALS-600 Power Amplifier to operate with my Yaesu FT-1000MP Mark V and increase my power output from 200 watts to 600 Watts SSB. #

The ALS-600 worked fine for about a month and then it intermittently began to shut down during both SSB QSOs and CW QSOs. #Since I'm a net moderator, this problem was very frustrating.

I contacted Ameritron Technical Support since the equipment was under warranty. #They recommended that I decrease my Yaesu FT-1000mp Mark V microphone input in order to decrease the input power from the Mark V to the ALS-600.

Of course I immediately realized that this was not the solution to my problem since the problem occurred both on CW as well as SSB. #

After doing some technical research, I learned that the ALS-600 has a thermal relay cutoff switch and when the FET heat sinks (there are four of them) get too hot, the thermal relay cuts off power to the ALS-600.

I decided to attack the problem as a cooling issue and installed two fans four times as powerful as the original fan that came with the ALS-600.

Unfortunately, my four-month old ALS-600 dropped dead on me four days ago. #No power output at all. #I sent it back to Ameritron for repair or burial.

Footnote: I received my repaired ALS-600 back from Ameritron about three weeks after I shipped it to them. #They replaced all the FETS free of charge. #It seems as if I was sold a lemon with four bad FETs. #I have since discovered other owners who had the exact same problem.

http://www.qrz.com/iB_html/non-cgi/emoticons/sad.gif

[k4lem]

My guess, if you are an NCS, you are probably doing a bit more than the duty cycle for the AMP. The solution may be extra fan or way to keep the sink cool. Commercial gear today for broadcast CCS service use large sinks and extra cooling fans.

That should work. Not owning an ALS 600 I am not sure how difficult introducing additional cooling may be.

[w8cbc]

I have to ask. You haven't been running 200 watts into the thing, have you?

[W3XAF]

No, of course not.

I run about 50 watts into my ALS-600.

[W3XAF]

Dear Ameritron Tech Support,

Re: #Model ALS-600, Serial #13999

After only three months, my ALS-600 is having problems again. #

This time, I can't get more than 400 Watts output power on 75/80, 40, 20, 15 &10 meters with an input of 80 watts from my FT-1000MP Mark V.

However, on 160 meters, I can get 550 watts output power with an input of 80 watts.

I have a Bird Model 43 100-Watt Wattmeter in series with the RF output of my FT-1000MP Mark V and a Bird Model 43 1000-Watt Wattmeter in series with the ALS-600 output.

This power problem just began this week. #Before this problem surfaced, I could get between 600 & 700 watts output power with an input of 80 watts.

Since Mr. Robin Hood replaced all four LLT, Transistors, FET, RF. TMOS, MRF-150 on 06/28/2006, I shouldn't be having this problem.

Is there a control inside my ALS-600 that I can adjust to increase the power output on 75/80, 40, 20, 15 & 10 meters?

If there is no control available, please advise my next course of action.

My amplifier is still under warranty since I purchased it on 03/25/2006.

[W3XAF]

Ameritron Tech Support personnel would not issue me an RMA for my defective ALS-600 so I purchased four FETs and repaired the ALS-600 myself by replacing a defective FET.

Now my ALS-600 works fine--but for how long--is anyone's guess!!!

[w8cbc]

Best of luck with it - maybe this time it'll settle down.

If not, I wonder if there are higher-spec FETs you can run in it to leave some head room.

Anyhow. I'll definitely be after something with a tube final. What I was hearing from you guys about solid-state amplifiers scared me off the things.

[G8ILD]

Hardley worth buying for the sake of 3Db get the 1Kw outfit then you are talking.......R