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Old 15th May 2018, 11:25 am   #15
Nymrod121
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Join Date: Apr 2012
Location: Worcestershire, UK.
Posts: 2,034
Default Re: Basic stereo FM signal generator

Belkin Tunecast

I've previously modified a Belkin Tunecast so that its RF output is now presented via a short length of 50 ohm coaxial cable with a bulkhead 'N' socket on the end (the latter being a re-purposed adaptor lead from some long-range WiFi experiments).

Just for the heck of it, yesterday I checked the Tunecast's output on an analyser (no baseband audio applied):

-32 dBm @ 88.1MHz
-24 dBm @ 107.9MHz

(NB: I noticed significant - i.e. 2-4dB - amplitude 'steps' at certain spot frequencies when going up/down the band by holding down the relevant button - I didn't note the actual frequencies at which this happened but if anyone needs that info I can repeat the test and post later)

Harmonics/sprogs/other misc. digital 'shash' generally < -45 dB w.r.t. carrier
19 kHz pilot @ -14 dB w.r.t. carrier
38 kHz subcarrier @ -32 dB w.r.t. carrier.

( @John_BS, russell-wb, swb 18 et al ... nowhere near CD2/11 / TM4/6 standard!! )

Cheers
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Last edited by Nymrod121; 15th May 2018 at 11:28 am. Reason: typo
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