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Reviews Categories | Amplifiers: RF Power - 6M/VHF/UHF+ | RM Italy LA250 VHF amplifier Help


Reviews Summary for RM Italy LA250 VHF amplifier
RM Italy LA250 VHF amplifier Reviews: 2 Average rating: 4.0/5 MSRP: $559.00
Description: The LA-250 is a 200W 140-150MHz amplifier, at 1 to 20W input (13.6V 30A). It uses 4 Mitsubishi RD70 Mosfets mounted on a copper heat spreader (200x60x3mm).

It is available in two versions one with and one without top mounted fans. There is an external PTT input but it can be used also without due to the built-in HF-VOX. The front panel features an LCD display which shows input power, output power, heat sink temp and output VSWR. There is the ability to change the intensity of the backlight.

The CPU keeps an eye on input power, temperature and VSWR and will if necessary disable the amplifier from transmitting if there is fault. Any errors will also be recorded and will be available for later recall for diagnostic purposes by either the manufacturer or his distributors.

Weight is approximately 4kg. Dimensions are approximately 240x420x70mm for the non fan version and an extra 10mm of height, 80mm, for the fan version.
Product is in production.
More info: http://www.rmitaly.com/index.php/en/products/amplifier/item/978-la-250
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AD7UF Rating: 3/5 Sep 23, 2016 22:11 Send this review to a friend
Powerful, with "rough edges"  Time owned: 6 to 12 months
THE GOOD:
- Glad I didn't get the fans -- I don't see that it would need it unless you were running 100% duty at high power.
- Amplifies as advertised. I tested at drive levels from 1/2-30W (5-25 in 1W increments), and actual output hit ~200W @ 5W and 250W @ 10W in. Casual SSB listening showed output to be reasonably linear at all power levels.

THE BAD:
- The amp's power meter's off. Input reads ~40% lower than actual. Beware - this also affects the over-input protection! Output also read 20-40% lower than actual, depending on level.
- The bypass isn't a 100% bypass. If you want to run a radio w/ more than 50W, or use UHF, you must completely switch this amp out of the circuit. I repeat: do not try to use 70cm through the amp, even in bypass mode.
- Not only does it lack a receive preamp, but with the amp in-line, I find that signals degrade by 6-10dB by my guess. Yes, it's bad. If I'm working a station weak enough that I feel the need to use the amp, I often have to switch the amp out (tedious - 2 coax switches) to still hear them.

THE UGLY:
The stick-on front panel wasn't aligned quite right and the screws forced it over. It unsticks and bulges out in a couple of areas. Disappointing for such an expensive piece of equipment.

THE GRAPH of the power readings and more details on my test methodology can be found at http://www.mmsherc.net/happenings/la-250
 
W1ZZK Rating: 5/5 Apr 16, 2015 11:21 Send this review to a friend
Great performance and reliablity  Time owned: 3 to 6 months
I have used this amplifier nightly for 3+ months with no problems. It's a winner!

When fed with 11 watts from my TS-790A the output is 204. Heat is no problem, even without the fans. With only 2 watts in, the output is 125 watts (this is where I run it mostly). The amp is physically very large.

I really like the display. It shows input power, output power, SWR and heatsink temperature. It has foldback and will operate to 2.8:1 VSWR. I have tried all the protection features and they work perfectly to protect the amp.

My only wish is that it had a low noise receive preamp.

Although I have had issues with previous versions of RM Italy VHF amplifiers, this new design is rock solid. I can recommend the LA250 amp.

 


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