| YS1RS |
Rating:  |
2024-02-25 | |
| Excellent Amp! Needs WARC to be 100% |
Time Owned: more than 12 months. |
Superb engineering in action by Drake. Bought it from the XYL of a SK YS ham a few years ago.
Needed complete recap, added protection MOVs, protection to use modern transceivers with this amp, soft start, and added the 10 meter band. The amp was ready for 10 meters, included the coil for it but required a very small mod to enable 10 meter band.
The big problem I had was that the amp meter was not working completely. Most of the time the meter was dead. Learnt how to adjust it by using a Watt-meter as a reference and worked fine. This amplifier is very simple to use, well engineered, strong, superbly built, the 3-500z tube is excellent, and has resisted a lot of abuse over the years by the lack of front panel meter, but continue working. No need to baby that 3-500z tube!
Recently, I was recommended at the Drake forum, a seller who was selling the same meter model as the original used by Drake (now discontinued) but with slightly different internal circuitry, so instead of FS=200uA these ones were FS=1mA.
I had to recalculate the whole meter circuitry network to match the new meter values, and now is working correctly, as per the manual/factory specs.
Now, I enjoy it fully, adjust it per the original documentation instructions and can see on the meter what is happening inside of it.
For FT8, I try not to exceed 350 Watts output, as that mode is very hard on the amp.
On SSB, it get's me through pile ups easily.
Only draw back I find is, the lack of WARC bands. This amp was built at the time the WARC bands didn't exist.
I can see other reviewers mention it works fine on WARC bands. Please share with me how you did it please.
Not many were built as I can see. My seria number is 3XX, very low.
In brief: I can not say other than "if you see one, grab it immediately!". They don't build them like this any more.
This amp will work for another 50 years and will survive after me, for sure!
Rob
YS1RS
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|
| WB2VVV |
Rating: |
2022-07-10 | |
| The BEST single 3-500Z amp! |
Time Owned: more than 12 months. |
| This is simply the BEST single 3-500Z amp out there, bar none. It is very well engineered and built. It operates smoothly and puts out solid power wired for 240 VAC. I do wish mine had 10m but it looks too difficult to add, so I enjoy using it on 160m thru 15m. Too bad the illegal CBers caused 10m band exclusions to be imposed on LEGAL Ham amps! |
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| K5JCJ |
Rating: |
2019-07-27 | |
| Built for the ages |
Time Owned: 6 to 12 months. |
| I heard how durable 3-500z based amps are but didn't know much about the heritage of Drake when I purchased this amp months ago. It's an amazing piece of engineering. The amp has tons of power available when needed, beautiful aesthetics, and that classic Drake look and feel. My only complaint is that the old style circuit boards didn't hold up very well when I had a repair tech re-cap it, and the traces were slightly burned and damaged. But despite that, it still works like a champ and likely will for another 40 years. |
|
| W8IDL |
Rating: |
2016-01-16 | |
| Solid Performer |
Time Owned: more than 12 months. |
| I use this amplifier with my Drake TR-5 transceiver and it is a solid performer. I bought it new with the TR-5 and was not sure if I'd be satisfied with a single 3-500z tube, but the L-75 has made me a believer! It is a simple, stable design and puts out 700 watts (+) with its self-contained power supply. Tuning is very smooth and easy and I have had no problems in all these years of ownership. The thing I've noticed is that they are rarely available on the used market, and the ones I see go for more than mine cost new! |
|
| N3IBX |
Rating: |
2009-02-12 | |
| One terrific amplifier if you can get your hands on one! |
Time Owned: more than 12 months. |
I've owned my L75 for close to ten years now, and other than replacing the original Eimac 3-500Z with a "RF Parts" branded Chinese 3-500ZG, it's been a superb performer. There is a (I think ) 47mfd? padding cap for 160M that you can still get from Drake at about $25 or so. If it becomes defective you'd be better off using a small doorknob or other type cap, and pocket the difference in cost.
I get a solid 900W output with 100W drive on all bands except 10M, where it will do a little less, maybe 800W or so. I modified my amp to run on 10M, since it didn't come with 10M from the factory.
It's perfectly happy on any of the WARC bands, and was built with a wide range pi net output in anticipation of the coming bands when the amp was built.
The L75 has a rugged self contained 2700V power supply, and in my opinion is the very best single 3-500Z amp ever built. It weighs about 70 lbs, and will fit on your operating desk next to your rig/exciter, which in my case is a Drake TR-7 tranceiver. I've also used it with quite a number of different rigs, from a Yaesu FT7-B to a FT-950, and it's performed flawlessly, even on AM. The two speed thermostatically controlled fan kicks in when the tube starts to get real hot, and is relatively quiet in operation. You can hear it just loud enough to let you know it's running on high, but not loud enough to show on your scope.
The only real drawback I can think of is that their relatively scarce. They do turn up on ebay and other sources from time to time, but in my ten years of operating it, I've only encountered one other on the air.
If you're lucky enough to get one, pay just about any price for it. In the long run you won't regret it. For a amp that'll do just under aKW output that fits on your operating desk, and will take a beating, you just can't find a better amp. Period!
GL and thanks for reading my review.
73, Joe Cro N3IBX |
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| VE3NYZ |
Rating: |
2008-02-23 | |
| excellent amplifier |
Time Owned: 6 to 12 months. |
An excellent amplifier that produces 600 watts output with as little as 50 watts drive.
Solid reliable construction in a self contained amplifier/power supply combination. Cooling fan is dual stage, running mainly on low speed and runs quietly. |
|
| IK0YKM |
Rating: |
2008-02-08 | |
| The best of category |
Time Owned: 0 to 3 months. |
Great, reliable amplifier. Easy to use and good power output (700/800 watts) with only 80 watts input.
See it:
http://www.wb4hfn.com/DRAKE/OperatorPictures/IK0YKM-Page02.htm
Is a dream. I'm very satisfied
73's de Henry IK0YKM
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|
| N5GLR |
Rating: |
2006-11-20 | |
| Excellent |
Time Owned: 3 to 6 months. |
Didn't know what quality was until I acquired this amp. Very smooth in operation. Accurate, easy to tune, consistent, strong, and a real pleasure to use. It's quite handsome too. I like the soft blue glow from the meter light.
I've found that "tuned input", on some amps, is a relative term but, not with the L75 ... perfect on the bands it was built for. Although not designed for WARC, it will work those bands FB with a little help from the internal tuner on my rig. I've found that it's forgiving when faced with a not-so-perfect SWR (book says 2 to 1 is OK and it's true).
50 watts from the exciter will easily produce 600 watts (on 20 mtr) when tuning. On rare occasion, I've "goofed" and driven it with 75 watts (or a bit more) and saw 900 watts on an accurate meter.
Speaking of goofs ... I fried one of the 8 power supply capacitors the day I brought it home. Long explanation cut short ... my fault entirely. I had difficulty finding direct replacement caps so, I found modern electrolytics within the capacitance "range" (same voltage) and replaced all 8. Seems to work FB but, with a bit more plate current.
I feel very comfortable highly recommending this amp to anyone who can find/afford one. They are fairly rare (not many were built) and value is increasing. I recently saw one listed as "new" on ebay and the bid was around $2k ... also saw another one listed elsewhere for around $1200. I think I got lucky when I found this one for far less than that.
Garry
N5GLR |
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| VR2AX |
Rating: |
2005-08-17 | |
| Reliable medium power classic |
Time Owned: more than 12 months. |
Reliable 1980 Drake amplifier, younger brother of the L 7 with power supply built in) still produces 600 watts key down out measured on a Bird 43. It can produce more however I limit plate current to 400 mA not 450 mA as stated in the manual. Keep grid current to 120 mA. Amp is even quieter than my L4 and L-4B. Consider installing a soft start to limit filament inrush current if used regularly.
Perspex/plexiglass/Lexan strip over meters tends to deteriorate but can be replaced easily. |
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