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Sets, Parts and Service Information Wanted (private buyers only, no swaps) If you need help obtaining components, sets or equipment, post a message here. Private buyers only - no traders. No swaps.

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Old 10th Oct 2018, 12:52 pm   #1
Alf
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Default SEM Sentinel VHF Pre Amp

Can anyone supply any info regarding the SEM Sentinel VHF Pre Amp? It's designed to be used in line with a transmitter being RF switched. When powered up, the internal relay is turned on, obviously, with no RF drive, it should'nt.

As the unit isn't frequency specific, is it some sort of wide band VHF amplifier?
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Old 10th Oct 2018, 3:55 pm   #2
merlinmaxwell
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Default Re: SEM Sentinel VHF Pre Amp

I would think that it is supposed to be turned on in the no RF situation, loss of power (DC) would then disconnect the receiver. Fail safe.
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Old 10th Oct 2018, 4:25 pm   #3
Nuvistor
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Default Re: SEM Sentinel VHF Pre Amp

Some information in this web link, it’s a review of VHF preamps including the Sentinel. Page 32.
https://www.americanradiohistory.com...RT-1983-11.pdf
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Old 11th Oct 2018, 12:02 pm   #4
Alf
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Default Re: SEM Sentinel VHF Pre Amp

Thanks for replies folks, it seems like there's a dearth of info on this pre amp, I guess I'll just have to play around with it.
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