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Reviews For: Alpha 91B

Category: Amplifiers: RF Power - HF & HF+6M

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Review Summary For : Alpha 91B
Reviews: 52MSRP: 2798.00
Description:
Replaced by the ALPHA 99.
Product is not in production
More Info: https://www.alpharfsystems.com/
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00524.9
ON9CC Rating: 2011-02-01
Excellent! Time Owned: more than 12 months.
I've bought my 91b about a year ago second hand from Bert PA1K. Since then I've only used it on 160m and 80m with great pleasure. It's quiet, produces a clean signal and is a pleasure to tune. If you're looking for an HF amp and can get your hands on one, don't hesitate; I would also buy it again.
W5HOW Rating: 2011-01-30
The Best Time Owned: N.A.
I have never used any other amplifier and it looks as though I never will!
LA4UOA Rating: 2010-12-17
top amp/top service Time Owned: 3 to 6 months.
Bouhgt my amp second hand,when i got it i had to do some mods,e-mailed Alpha and they answered me same day,with a list of mods with pictures ,so mods was very easy to do,Thank you very much Glenn.
Amp has plenty of power,with low drive,very easy to tune up,and runs all day long and never overheating.Have the extra fan but never used it.
I love mine.
EA1DR Rating: 2010-12-17
Simply; FANTASTIC..!! Time Owned: more than 12 months.
I can only say that they are fantastic.
I had the opportunity to try a 91B in the W0LSD QTH, my friend Ken, and I can only say it was a great experience. It is quiet, its superb valve, and easy operation ..
Simply fantastic ..! I can recommend this linear to everybody.
N3AF Rating: 2010-12-11
Excellent (!!) Time Owned: more than 12 months.
I purchased my Alpha 91B in December 1997. After 13 years of solid performance, I thought I'd add my endorsement and high fives for this super amplifier. I've had zero problems. Still using original tubes with full output! No issues whatsoever.
PT7CB Rating: 2010-11-17
For serious contesters Time Owned: more than 12 months.
I have three Alphas ( 99, 91B and 374 ) at my contest station ( ZY7C/ PW7T ).
The 91B is in one of the running stations,and I didn't have any problem with it in the past years.
It is always a pleasure to receive nice reports from the DX stations.
I am certain that Alpha will ever be in my shack!
Barreto - PT7CB
K1LI Rating: 2010-01-30
Workhorse Time Owned: more than 12 months.
This amp has been going strong for over 10 years. Used in many contests on all bands. The only repair was to replace the vacuum relay - twice - because I was running it "full QSK." I don't do that any more, both to save the relay and to reduce the noise.

This unit is a great testament to Alpha's commitment to bring high-value products to the ham market. Hats off!
N1JMS Rating: 2009-03-01
Rock Solid Time Owned: more than 12 months.
Smooth, quiet, strong.
K9XK Rating: 2006-03-10
One of the Alpha Standards Time Owned: 0 to 3 months.
I would say that the 91B is one of the more robust, and pretty (after all, we like our stations to look good, right?) amplifiers available. I have an 87A, and have had a Drake L-7, Icom IC-PW1, and Emtron DX-2sp. Even with the auxiliary fan, the 91B is quieter than the Emtron or Icom by quite a bit. The Emtron delivers more power but is not as nice looking, and the Icom was auto-everything but put out less power. I took the middle road because I already had an Alpha 87A that was a great overall compromise.

The 91B will do 1.5kw with plenty of headroom. I have accidentally abused it by transmitting into the wrong antenna, but it didn't raise an eyebrow - it kept cranking because, well, I guess it felt that I "meant well". The 87A would have faulted right away. In some respects, that is a good quality. But in the real world, a non auto-tune amplifier like the 91B should be ready to take abuse, and it does that pretty well, it seems.
PA1HR Rating: 2004-07-03
Very solid and reliable PA Time Owned: 6 to 12 months.

I have used this linear amplifier for a while and I was very satisfied with it.

The technique and the used parts are conservative but strong and very reliable.

The look is very good; especially the LED-bars who IMHO look better then the single LED's of the later Alpha linears.

The noise of the ventilator is certainly not annoying. Same with the vacuum relays.

The GU74b tubes are reliable, easy to get and cheap.

The after sales service of Alpha Power is excellent, friendly and remarkable fast.

The review of Walt W0CP on http://www.evansplaza.com/w0cp/images/eto91b.pdf tells you more about this excellent PA.

Second hand prices is between 2000 and 2500 dollar or euro.

I can recommend this linear to everybody.

I changed it for the Acom 2000A which has about the same reliable HF unit.

Alpha and Acom linears are the best you can get.