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Reviews Categories | Amplifiers: RF Power - HF & HF+6M | KW ELECTRONICS Help


Reviews Summary for KW ELECTRONICS
KW ELECTRONICS Reviews: 4 Average rating: 4.5/5 MSRP: $105.00 POUNDS
Description: KW1000 AMPLIFIER-KW600 AMPLIFIER
Product is not in production.
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N5HNY Rating: 5/5 Oct 24, 2011 20:16 Send this review to a friend
Good Amplifier  Time owned: 0 to 3 months
I was looking around for an amplifier to replace my Dentron GLA-1000. I decided to go with something with 572Bs. They run the power range I like (500 watts out or better) and they are an economical tube.

I couldn't find a SB200 or FL1200B for a decent price. Even the broken ones were bringing $300 to $400 before shipping. I looked around and found a KW-1000 for sale in Canada. I was told that one was gone but that a fully operational one was available for a few more dollars. I said what the heck and went for it.

When I took it out of the shipping box, it was what I expected. I little wear and tear here and there. Missing screws and the lot. When I threw the main switch I got sparks. I thought "uh-oh" but it turned out to be the cooling fan hitting the main RF choke. That was remedied and a SO-239 replaced the input PAL connector on the back.

Fifty watts drive produced 600 watts and on air reports were good. So far it's been a good amp.
I'm going to put a plug on the back for the keying circuit, replace the missing screws, and repaint later.

I paid $275 US for mine. It cost me $61 to ship it. The Penta 572B tubes are still going strong.
I don't care for the big honking bezels that tell you when the mains are on or the SWR meter is in play. The power supply is super quiet with almost no hum at all when running full power.
 
G0MJK Rating: 4/5 Oct 25, 2008 15:46 Send this review to a friend
KW1000  Time owned: 0 to 3 months
These amplifiers were made to match the KW2000XX range of transceivers but were also sold to UK Government for diplomatic wireless use in a channelised version. I have just acquired a good example from a white stick operator who cannot use it safely any more and I intend to use it with my Yaesu FT101E and 101Z. These are built like brick outhouses and will stand some abuse and bad VSWR a weak point is certainly the sparse manual but mine came with a copy of the manufacturers blueprint showing revisions to 1972. Please remember that 2.4KV will kill you and not to mess with these if you don't know what you are doing as it does not have the safety interlocks that more modern equipment has. This will certainly do 800 watts SSB for 40 watts input so no need to run it hard either. Recommended especially with older valve equipment.
 
9V1PC Rating: 4/5 Jun 26, 2006 20:33 Send this review to a friend
Good honest amplifier!  Time owned: 0 to 3 months
Picked up a KW1000 on UK ebay- going cheap.

Gave it a good clean up and replaced all the crusty old electrolytic caps - added six 390uF 450V in the HV supply with new 120Kohm 2 watt bleeder resistors across each. Remember to replace the caps in the -ve bias supply voltage quadrupler too- two were short circuit in mine. There should be about -35v DC on the grids during RX- cutting the tubes off nicely.

Add a new 1N5408 six diode string (3 plus 3) in the HV chain and a new 1N5408 in the relay supply (open circuit in mine originally).

Finally added a reverse-biased 1N4007 across the relay coil as a transient suppressor to quench those switching sparks!

Added a 15ohm 5 watt glitch resistor in the plate supply and a couple of cheap new China 572B's.

With some re-tuning of the input filters (they are quite broadband)- decent coverage of the existing bands AND WARC bands can be achieved.

40m bandswitch position will tune 30m and 40m nicely. 20m position will tune 20m and 17m.
15m position will tune 15m and 12m.

Re-neutralise on 10m band and hey-presto! An honest 500watts CW out on ALL bands! Nice and stable in operation too...

Nice thing with this old amp is that the relay switching is at only 8 volt DC (but note the switching line needs to sink 500mA...).

ONLY WORK ON TUBE AMPS IF YOU KNOW WHAT YOU ARE DOING- 2.4KV CAN KILL!!!

73's

Pete


 
M5LRO Rating: 5/5 Dec 5, 2004 14:50 Send this review to a friend
Great Stuff  Time owned: 0 to 3 months
I really rate this good old amplifier from what was a great English Ham Radio company.
I have owned mine for a few months (bought secondhand froma radio fair) and after some mods I am very happy with it.
It certainly compares to all the other dual 572B linears such as 2100Z and Heath SB200 with some nice features. The only thing is that they are now out of production for about 25 years but still going strong. Nice design very robust and great to work on only fault is the sparse manual and no manual bias adjustment but then you can tune the input on seperate slugs for each band.
Not the ultimate but for the money takes a lot of beating.
Chris
M5LRO
 


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