1w stereo transmitters from greece any good

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radionortheast
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1w stereo transmitters from greece any good

Post by radionortheast » Mon May 20, 2019 9:52 am

they look like their controlled by a pic

https://www.ebay.co.uk/itm/FM-PLL-TRANS ... 2797148908?

Albert H
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Re: 1w stereo transmitters from greece any good

Post by Albert H » Mon May 20, 2019 1:32 pm

Those appear to be the exciter boards that the "Woodstarr" uses in his rigs. I've never tried one of these myself, but some of the gear coming from Greece is actually very good.
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teckniqs
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Re: 1w stereo transmitters from greece any good

Post by teckniqs » Tue May 21, 2019 9:15 am

I tested one of these Greek eBay boards about 8 years ago (around 88MHz) and the second harmonic was as powerful as the fundamental (main carrier freq).

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Re: 1w stereo transmitters from greece any good

Post by Albert H » Fri May 24, 2019 3:09 pm

I just found an exciter here that's labelled in Greek, in a box of junked boards. It's a free-running VFO job, and has an MRF237 final. It's just three stages, and looks similar to the old Dutch "Stentor" board. I fired it up into a dummy load, and found that the oscillator is on 49 MHz, and the output is 98 MHz. At switch-on, it starts about 200 kHz low, and drifts upwards over about three minutes until it's bang on 98 MHz output. It's doing a nice 4 Watts, running warm (but not hot), and the harmonic content is acceptable (it has a low pass filter on the output). Stability isn't too bad when it warms up! LB tells me that "a Greek bloke from Patras" sold these for about £15 each. Looking at the board, it wouldn't be too difficult to add a PLL.... I'll get a couple of pix of it later on.
"Why is my rig humming?"
"Because it doesn't know the words!"
;)

radium98
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Re: 1w stereo transmitters from greece any good

Post by radium98 » Fri May 24, 2019 9:55 pm

if it is smart kit 1028 so it is a very bad oscillator i cut the oscillator stage and use the amplifier only drived by pira 1w
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radium98
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Re: 1w stereo transmitters from greece any good

Post by radium98 » Fri May 24, 2019 9:57 pm

it does not use an mrf237 the original one use as bf stage bc547 and oscillator and buffer a couple of 2n2219a and a final as 2n3553 that warm a lot ,after a burn few fried very warm ough ,i changed to c1947w the output is powerful but as a transmitter is null a clever idea is to put other pll and drive it

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Re: 1w stereo transmitters from greece any good

Post by Albert H » Sat May 25, 2019 2:41 am

Those "Smart Kit" things were awful! The one I have is marked "Unique Electronics" and is a very different shape board to the Smart effort. It has a metal flange for the heatsink for the MRF237, and it also provides screening and a couple of mounting holes. It's quite well thought-out, and the designer knew what he was doing.
"Why is my rig humming?"
"Because it doesn't know the words!"
;)

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