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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: 49MSRP: 2798.00
Replaced by the ALPHA 99.
Product is not in production
More Info:
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
W0RMS Rating: 2019-07-24
GREAT AMP Time Owned: more than 12 months.
Have had this amp over 5 years no problems at all. It just sits there and makes buckets of power with little drive. The fan is quiet and the displays let you know what is going on. If you do make a mistake (wrong band etc.) it will save you, The only con. I have is the warm up time to come on line. If you find a nice one grab it! WØRMS

W4YB Rating: 2018-01-06
Wonderful amplifier over all Time Owned: 0 to 3 months.
I just picked this amp up from a friend so have operated only at his shack. Very anxious to get it set up in my shack. We were driving it with a Flex 6500 and easily obtained the legal limit with just 25 watts of drive. As others have said it loafs along with legal limit and is a dream to tune. Esthetically I think it’s a 5 also. Not sure if i’ll Ever upgrade but that remains to be seen. I think it’s going to be a dream machine, for me anyway.
NO2C Rating: 2017-05-10
Bought Used - It Failed - Sent to Alpha for Repair - WOW! Time Owned: 3 to 6 months.
I bought the amp used. After about three weeks the transformer failed. The fan also failed. Emailed Alpha and discussed options with Glenn. I decided to send it out to them and have it repaired.

They fixed it up, updated the controls and now it acts like a 99. They sent me an transformer made in the USA and put in a fan made here also.

I now get the full legal output on much less drive.
N6ERP Rating: 2016-11-10
Great Value Time Owned: more than 12 months.
Highly recommended. Simple to operate, it loafs along at legal limit w/ plenty of headroom, fans and relays are quiet, it's almost dummy proof, and just works. Easy to forget you are running an amp. And, people just "hear" you. 4CX800 tubes are rugged, yet inexpensive.

I hear a lot of talk from people saying they are modifying their amps of other brands, adding soft-start, QSK (vacuum relays), soft mounting the blowers to reduce noise, etc. The 91B already has all that..
PA3HGT Rating: 2015-10-20
Great to have Time Owned: 3 to 6 months.
Had this amp for half year but due some "neighbour" problems at my holyday-QTH had to sell it.Implemented all mods in it and when you know how to tune it's a nice amp to work with.Tuning is a bit strange in the beginning but it's ok after when uoy used on it.Plenty of power is available and you won't be dissapointed.
I have on my website a lot of photo's (dutch written,Google translate available) :

N2DY Rating: 2015-02-05
Effortless Power Time Owned: more than 12 months.
I have owned my 91B for almost 18 years. It still works great on its original set of tubes. It operates just as it did on the first day I received it. It loafs along at the legal limit. Fortunately for me, it is idiot proof as its protection circuits tripped whenever I have done something wrong like using the wrong antenna (or no antenna) or having the band switch in the wrong position. I cannot see myself ever parting with this amp (at least while I am alive). If you can find a clean one used, go for it.
K5DSQ Rating: 2015-02-05
91b Update Time Owned: 6 to 12 months.
It's been just about a year since my 91b arrived (see previous review) and operating it daily can only be described as extremely boring. It just continues to perform without a hitch. Needless to say I could not be happier. It easily runs legal limit every day and like a heavyweight prize fighter it just stands there and harasses my exciter with "Come on you lightweight punk, is that all you've got?" The tubes still put out the exact amount of power as the day it arrived. Even the band settings (Load & Tune) load at the same spot where I originally set them for each band. If you miss or enjoy the excitement of smoke, arcing and/or component failures I suggest you look at something other than a 91b. With legal limit high power amps, boring is the way to go!
ZL4PLM Rating: 2014-02-06
Superb Amp - Well built and goes like a tank! Time Owned: 0 to 3 months.
I bought mine second hand from Tommy WD4K and gave it a new home here in NZ.

I have owned a few HF amps but this is the dogs ... It is without a doubt one of the most robust amps I have ever driven. It's extremely well built, solid and reliable. Built like a tank you won't break this one! You're average ameritron its not!

I've been running this is pileups and DXing and its spot on. Easy to tune, keeps piling out the watts even after hours calling FT5 but its worked wonders!

I heard they were good, indeed they are! No wonder it gets a 5 * rating ! I'll add to that!

Now .. I need to see if I can trade my SPE amp in for one of those nice auto tuning Alphas with out the XYL noticing!!

If you get a chance to buy one... do it! You will NOT regret it :) So make some space and grab an Alpha!

thanks Tommy .. sorry it isn't coming home :)

BTW there is plenty of videos on youtube of them and loads of info around inc here on Eham - chek it out and then hunt one down - they are not easy to find ... theres a reason for that :) Once you have it - you won't be selling it!


Simon ZL4PLM
W3FL Rating: 2013-12-21
GREAT THE BEST AMP Time Owned: more than 12 months.
have had this amp for 15 years works like the day i got it.......Marsh "W3FL"
N9LBW Rating: 2013-12-14
Excellent! Time Owned: more than 12 months.
The Alpha 91B amplifier is very dependable. I got mine used and for the money it is hard to beat. I would recommend it for anyone.