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Reviews Categories | Amplifiers: RF Power - 6M/VHF/UHF+ | LinearAmpUK 70cms Discovery GS31 Help

Reviews Summary for LinearAmpUK 70cms Discovery GS31
LinearAmpUK 70cms Discovery GS31 Reviews: 3 Average rating: 4.0/5 MSRP: $GBPounds 1495 with tax
Description: 70Cms U. H. F. Triode Amplifier 700watts output for up to 100watts input.
Product is not in production.
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G8ASI Rating: 4/5 Feb 24, 2011 08:45 Send this review to a friend
Very Good  Time owned: 0 to 3 months
Apart from some warm up drift of the tuning, this amplifier outputs an enormous amount of power on 70cm. I do feel that the blower is a little under rated as a previous owner wished to run television and found that the amplifier overheated very quickly. However I am delighted with this amplifier and have few reservations, and am looking for the 2m version. In the past I have used the 6m amplifier from this manufacturer that used the 3-500 tube, and also found it to be very good.
M1IFT Rating: 3/5 Jan 11, 2009 03:20 Send this review to a friend
Questionable engineering practices  Time owned: more than 12 months
This amp arrived secondhand but almost brand new, as it was only used in 2 contests.

After testing it produced 650watts from 55 watts input (rms).Measured on Bird 43. It does drift a little if the output is more than 300watts, this is mainly due to the unadeqate cooling. The anode vent holes do not match up with the case, I am told this is to stop anything from being dropped through onto the anode, this could have been designed better.
At some point in the near future the fan will be upgraded and an extractor placed on the anode grill.

I have changed the input relay to a substantial real one, the old one used RG58 cable, considering it is 100watts input on 70cms max this relay was a poor choice. There is a lack of a sequencer.

The HT reservoir caps on the voltage doubler are at bare minimum to allow this amp to run to max, the uk limit is 400w unless you have an NOV.

When testing at full rate, the power supply sags, as all the different voltages are taken from the HT transformer (bad practice) all the LV circuits sag too, the illumination on the meters dim under load. So the next upgrade is a regulated 12volt supply for the control board and illumination, and possibly a separate supply for the heater.

A switch on the front allows Grid current or RF measurement, this is hopeless as a power meter but at will at least show that some rf is present.

The original owner of uk linear amp has retired now, I have spoken to the new owners, they are most helpfull, although won't supply parts anymore as a 'kit' to build your own ie pre built cavities etc, but will supply some spares.

All in all it's not a bad amplifier, easy to repair if you are competant with HT circuits, the gs31 are easy to find and inexpensive. However these amplifiers are quite expensive new and I wouldn't have bought one new.

Another 200 or so needs to be spent to get this amplifier working as it should.
G4OCO Rating: 5/5 Jun 8, 2006 09:17 Send this review to a friend
Awsome amp  Time owned: 6 to 12 months
For a long time I looked around for an 70cms amplifier for my contest station, came across the 70cms discovery from Linear Amp and ordered one. Apart from the original GS31 tube tripping the protection circuits upon power up, tube replaced free of charge with no hassle, thank you Peter of Linear Amp.
So you ask, is it any good and worth the money, a short answer is YES. It performs flawlessly when required, it is docile to tune up and once tuned up operates all day long without retuning. I do not have a meter capable of measuring the output power, but it is certainly more than the advertised output of 700w, a definate keeper. So if you dreamed of operating on 70cms at high power, with no hassle and not having a noisy fan causing greif, this amplifier is for you, thank you Linear Amp.

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