Manager


Manager - NA4M
Manager Notes

Reviews For: Amp Supply LK-500-Z-all models

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

eMail Subscription

Registered users are allowed to subscribe to specific review topics and receive eMail notifications when new reviews are posted.
Review Summary For : Amp Supply LK-500-Z-all models
Reviews: 21MSRP: 1,295 in 1988
Description:
Runs a pair of 3-500Z tubes, Legal Limit output, built like a tank! Covers 160-10 meters. K4ICL repair site has info but is down ATM
Product is not in production
More Info:
# last 180 days Avg. Rating last 180 days Total reviews Avg. overall rating
00214.9
KC2LCZ Rating: 2003-11-25
LK-500ZC Time Owned: 6 to 12 months.
I'm getting legal+ on all bands excluding WARC. It uses top notch components and is easy to tune. A new amp of this quality utilizing 3-500z tubes will cost close to 3k and may not provide legal limit. I sent the amp down to Bill at Omega Electronics to have a vacuum relay QSK circiut and a step start added. While it was there he also replaced the aging wiring harness and noisey fan bringing the the amp to "like new" condition. The LK-500ZC will normally sell for under $1,000. on the used market. Big bang for the buck! If you can find one grab it, you won't be disappointed.
WO2E Rating: 2003-09-09
LK-500ZC Time Owned: more than 12 months.
I HAVE THE LK-500ZC THE PLATE TRANSFORMER WENT BAD. I SALVAGE A PLATE TRANSFORMER FROM AN AMERITRON AL-1500 AND A SEPARATE ENCLOSURE HAD TO BE BUILD TO ACCOMODATE THE BIGER TRANSFORMER I SET IT UP FOR 120 VAC.I USE THE SAME FILTER CAP BOARD ETC. BUT WHAT A DIFERENCE NOT TO BLOW THE CAPS I USE A VARIAC HOOK TO 120 VAC WITH JUST 105 VOLTS IT GAVE ME ALMOST 3800 PLATE VOLTAGE AND JUST 45 WATTS INPUT IT GAVE ME 1200 WATTS OUT. I DID NOT WENT OVER THESE NUMBERS THE HOUSE CURRENT WITH 120 VAC WAS NOT HAVING IT AND FILTER BOARD ETC WAS NOT SET UP FOR THE EXTRA LOAD. BUT THE LK-500 REALLY KICKS A$$ WITH THIS PLATE TRANSFORMER SET UP FOR 220 VAC. NOW I WOULD NOT BUTCHER A CLEAN LK-500 THAT WAS WORKING 100% ESPECIALLY WHEN ANY MOD WOULD REDUCE ITS VALUE. OVER ALL ITS A GREAT AMP AND EASY TO SERVICE AND SIMPLE CONSTRUCTION AND IT WON'T BREAK YOUR POCKET. I LIKE IT AND STILL USED AFTER 8 YEARS.
W1ES Rating: 2002-10-17
Good Amp for Low Bux! Time Owned: more than 12 months.
Bought mine back in the 1980s and have used it for DXing and contesting all these years. It's built very well and has been a real warhorse!

The shortcomings, some of which have been mentioned here by others, are the QSK circuit (you can't run the amp in standby if it's wired for QSK without an annoying sidetone), high filament voltage (corrected), king-kong band-switch detents(corrected-- removed one of the two ball bearings-- what a difference!)and lack of step-start for the PS. THere is plenty of room inside to do mods, however, and I've done several: extra cooling holes to the outside through a level beneath the deck, voltage-dropping wire to bring fil voltage to 4.75V and AG6K mods to anode & grid circuits.

With a good QSK circuit (which I swear I've been meaning to get around to playing with for 15 years but haven't) this represents the absolute best bang-for-the buck out there! Because the brand is an orphan, you can get them for a lot cheaper than they should be selling for! Frequently, you can get these for less than an SB-220 and it is a MUCH (I can't stress this enough!) better amplifier that also does 160m!
W5MG Rating: 2002-10-04
Built to last!!! Time Owned: 6 to 12 months.
I have owned my LK-500ZB for 6 months. This is one of the finest amps I have ever owned. I own an Alpha 78 and an Alpha 76CA. If Alpha had built an amp that ran 2 3-500z tubes they would have built it like this amp. If you have an opportunity to purchase one jump on it. You won't be sorry.
KG4ENZ Rating: 2002-08-08
LK500ZC Time Owned: 6 to 12 months.
I OWN A LK500ZC MODEL AND I AGREE ITS A RELIABLE TOUGH AS A TANK AMP.IT PRODUCES 1500 WATTS WITH A 100 WATTS OF DRIVE AND I DO LIKE THE ALO PROTECTION CIRCUITRY THAT PROTECTS IT FROM BEING MISTUNED AND CAUSING DAMAGE TO UNIT.IF YOU CAN FIND ONE ,ITS WORTH THE MONEY.KG4ENZ
W4VD Rating: 2001-11-09
Great Amp Time Owned: 0 to 3 months.
I bought this amp on ebay a few weeks ago and I am very pleased with it. I have the "ZC" model. It has a Kilovac vacuum relay for QSK and works like a dream on VOX, I get right at legal limit output on most bands, and the WARC bands are very acceptable, with 1200-1300 watts out on 12 and 17 meters. The tuned input is excellent, even on the WARC bands. The solid state tranciever likes the LK50ZC very much. The 2 speed fan is handy during heavy duty operation. The 6 to 1 reduction drives on the tune and load control make for a very smooth tune up and the dial scale makes for easy "tune by the numbers" once the settings have been determined and logged. All in all it's a good amplifier for the money and Omega Electronics has the parts and expertise to keep it running long into the future.
W8JJW Rating: 2001-10-04
Really Solid Amp Time Owned: 6 to 12 months.
I bought this amp at Dayton this year..been using it on 160 mostly on a wire and on 17-10M through beams with excellent loading and output. I typically run 1kw with 30-40W input depending on the band. I have the LK-500ZC. Built like a tank.
G4VGO Rating: 2001-07-14
Awsome! Time Owned: 0 to 3 months.
My amp is the LK-550 NTC (No Tune, Three Hole 3-500's) and it is a very good performer. This is the second Amp Supply unit I have tried, the first being the LK-850 with three 3CX800's in it a few years back.

On CW the QSK is smooth and does a great job with my FT1000D. The only problem is minor, a change in the L/C ratio of the 160m band is called for as is a beefier set of caps in the output circuit because the caps will heat up at full power out on that band. However, at legal power over here, it runs STONE COLD on all bands, all day long, 24 hours a day in a contest.

Very good value for money, and I am sure it will be contesting long after I am gone.

If you can buy one, do it, the external Peter Dahl transformer makes a good foot rest and at 1.2 KW+ on RTTY, a good foot warmer I am sure.
K6EGW Rating: 2001-06-16
More than good Time Owned: more than 12 months.
Instant on. I have beat mine up for many years. Instructions say "tune for maximum smoke." 1.2 KW
output on all bands.

I now listen to the boss and turn down the input. The tubes do not like 100 watts.

QSK. I never use the fan in high position. Same tubes. My God, what more could you ask for. Built like a brick. The instant on gets me on in front of many.

Get one if you can find one. 73's
N2NFG Rating: 2000-11-28
SOLID PREFORMER Time Owned: more than 12 months.
When I bought this amp 8 years ago, it arrived badly damaged from a fall off a UPS truck. (not US, we don't drop things!) After a trip to OMEGA amp repair, it was as good as new and gave excellent service for several more years, until I developed a liking for RTTY. Even keeping it well within the limits of the manufacturer, the solder would melt from the pins of the tubes. (I will admit that this was still under extreme use, RTTY contesting) But now I had the good fortune of living only a short drive from OMEGA, so in the truck it went for a ride to Knightdale, NC. Bill took a good amp and made it even better. For anyone who runs a ZB or ZA, especially for contesting or continuous duty modes, the mods that Bill at OMEGA can do are highly recommended. First, the deck holding the tube sockets is replaced with one with perforations to allow better cooling of the tube pins. Second, a plate is installed between the tubes and tuning circuit to allow more air to flow past the tubes. Third, a beefier fan is installed for even more air flow. Last, a temp. sensitive switch is installed to kick the fan up to high automatically. I don't expect any tube failure for a long, long time:) Other mods worth considering are the QSK board, and step start protection. (the original QSK scheme leaves a lot to be desired) I know that this sort of turned into a review of OMEGA, but these amps are getting kinda old, and there are a lot of them floating around out there. For a very reasonale price, these amps can be retrofitted with features that will turn one into a better two tube 3-500Z than anything currently available new. 73, Bob N2NFG