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Old March 8th 10, 07:02 PM posted to rec.radio.shortwave
Michael Black[_2_] Michael Black[_2_] is offline
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First recorded activity by RadioBanter: Mar 2008
Posts: 618
Default C Crane SW was not designed for DRM reception :No 12 kHz Output

On Sun, 7 Mar 2010, gccradioscience wrote:

I was thinking about getting a new C Crane SW so I can receive distant
digital radio monodiale radio stations, but I was reading somewhere
else that the portable radio receiver only has a 455 kHz output IF AM
jack. That got me disappointed, cause I have to get a down-converter
box or circuit to add to the radio receiver.


There's a lot more use to a 455KHz out jack than a 12KHz out jack. An IF
out jack was never common, but neither were they completely rare. You'd
use it to add an SSB adapter or an FM detector. Or add an IF based
RTTY detector. Place it early enough in the IF chain (ie before the
filtering) and you could connect a panadaptor to see what was going on.
It was great for experimental use, since you could do all kinds of
modifications without having to modify the receiver.

Indeed, the one mod many might make was to add a jack to feed the 455KHz
IF out of the radio.

12KHz is pretty much for only one purpose, your DRM converter. Well there
are other uses, but might as well stick to the standard. Why should the
radio add another conversion stage to suit your needs, when it isn't
likely to be needed by many? The 455KHz jack adds little to the cost, but
saves you having to modify the radio. Anyone doing any playing around
would be capable of adding that conversion stage, if they needed it, to
any project that they wanted to tack onto the radio.

FOr instance, if I wanted to use that good 250KHz mechanical filter I have
lying around, I'd have to add a conversion stage to use it with just about
any radio. But with a 455KHz jack, I'd only have to convert to 250KHz.
If all the radio had was a 12KHz jack, something I don't need, I'd have to
convert that back up to 250KHz externally, adding another stage of
unwanted and unnneded conversion.

Michael