I need about 10 volts RMS sine wave into a 50 ohm load, to test an aircraft eddy-current transducer simulator, around 15 MHz. That's 2 watts, so I might want a 3 or 5 watt linear amp. The ham stuff is mostly higher power and expensive. Mini-circuits has its ZHL-5W-1, which needs an external power supply and costs $1020.
Is there any nice boxed RF amp in this range? I can supply a few volts of sine wave from one of our ARBs.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
I ordered one of these. This design seems to be generic.
I am doubtful about the 3 watts. Identical boards seem to be 1.6 watts.
This one is 32 watts!
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
Something's not right. Check out the pictures of the "32 watt" version... It's actually the 3W PCB. I thought it looked the same as the previous one ! Maybe they really meant 32 dB or something in the main text of the ad ? AND only $28 instead of the $24 for 3W ? Somethings funny there.
$ENGINE-searching on "qrp hf amplifier kit" turns up some ham stuff which might suit your needs.
He can use the "3W" amp to drive the 10W amp.
--
Thanks,
- Win
I'm not an RF guy, but could you do that with an omamp and fet or bipolar, class A? I guess that needs some wicked coupling caps or a fancy transformer.
George H.
15MHz is quite close to the 20 meter (14MHz) ham band. I could couldn't find anything for 20 meters that ready to use.
If you want to build something, there was a previous 2013(?) discussion in S.E.D. on using two LT1210 amps in a bridge amp. +/-15V power supply, +/-10v output swing, 1.1A ouput current should do the trick. See Pg 20 for the app note. LTspice: The schematic is for a broadband amp but would probably work better with a narrow band 15MHz parallel resonant tank circuit and impedance matching transformer.
Yet another PA (power amplifier) kit:
45 watts RF. Runs on 12VDC. Broadband (3-30MHz). $15.Plug and play:
2MHZ-700MHZ 3W HF VHF UHF FM transmitter RF Power Amplifier $11.You didn't mention anything about modulation or linearity, so maybe Class C will suffice:
3.2W 35dB 1MHz-700MHz Power Amplifier VHF UHF FM HF RF Module For Ham Radio $16.This one is a stretch at 2W, but might work:
1-930MHz 2W RF Broadband Radio Transmission Power Amplifier FM HF VHF $17.4W 10-1000MHz RF power amplifie broadband RF power ampl $81.
100KHz-60MHz RF Power Amplifier 5W Liner Amplifier RF Broadband HF Amplifier $88.-- Jeff Liebermann jeffl@cruzio.com 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558
It's a bit much for an opamp, but a brute-force class A mosfet, maybe with a tank in the drain, would work. Nuisance.
I'd rather buy than build. This will be used to test an i/q modulator box that I don't really want to make. A very good customer wants a few, so we can't say no.
Ham stuff is mostly kilowatt range and shockingly expensive.
-- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com
It's a bit much for one op amp, but a couple operating in parallel wouldn't have any trouble. Making sure that they all shared the load equally (or eq ually enough) might get moderately complicated. A bunch of windings on a ni cke-zink-ferrite-cored transformer with a slightly stepped up output might be the easiest way to go.
As you keep on telling us. So does every last one of us.
Getting a small special purpose transformer wound shouldn't be all that dif ficult.
Kilowatts do cost kilobucks. Be grateful that it isn't hi-fi.
-- Bill Sloman, Sydney
John Larkin wrote in news: snipped-for-privacy@4ax.com:
_Cir
&keyworPretty wild that it requires a one megawatt input to put out only 3 watts. I guess you gotta read the fine print. Hahahahah!
He mentioned testing an I/Q modulator. It smells of a linear amplifier.
-- -TV (OH2UG)
Am 08.12.18 um 01:02 schrieb John Larkin:
Have you seen the new THS3491 ? LMH6702 on steroids.
<The right thing to distribute everything from 1PPS to 200 MHz.
In the basement, I still have a few 30W class A amplifiers. We used a lot of them in an ultrasonics phased array for material testing. We had some concerns about focusing that much ultrasonic power in a rocket booster, but there were no incidents. :-)
Cheers, Gerhard
** This might do the job:
150W is more output power than you asked for - but that makes it useful for other jobs and likely very ruggedly built.
.... Phil
Most of
If you need discretes to build one try RF Parts Inc.
Steve
We have THS6022 in stock, which is fast enough. Either would have to be used in bridge mode to get enough swing, with a transformer. That's another project. I was hoping to buy something.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
That design seems to be generic:
so if one doesn't work, we could always buy another.
-- John Larkin Highland Technology, Inc lunatic fringe electronics
Yep, he needs 4w pep for 10v rms. Cheers
-- ----Android NewsGroup Reader---- http://usenet.sinaapp.com/
One of the reasons i suggested communication concepts is they seem to run under the Fcc's radar and for decades have marketed a qualty product without certication or type approval.
Selling high power broadband amps that can be modded for 27-29 Mhz gets you squarely in the face of the FCCs enforcement division.
Steve
** This lower power version may be the pick of the litter:
Very compact, cost around $74, 4 x TO220 MOSFETs and the pic at the bottom of the page shows it is nicely made with no unusual parts.
.... Phil
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