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-   -   sync detector for NDB/beacon hunting? (https://www.radiobanter.com/shortwave/110898-sync-detector-ndb-beacon-hunting.html)

john December 3rd 06 10:55 PM

sync detector for NDB/beacon hunting?
 
hi all,

will a sync detector buy me anything on LW???? i'm mostly into beacon
listening under 540 khz.

thanks, john


Somebody Somewhere December 4th 06 12:36 AM

sync detector for NDB/beacon hunting?
 
john wrote:
hi all,

will a sync detector buy me anything on LW???? i'm mostly into beacon
listening under 540 khz.

thanks, john


Probably not. Even though ND beacons use AM emission, SSB or CW are the
best modes for hunting weak beacons. I prefer to use SSB and whatever
filter is narrow enough to kill adjacent frequency QRM in a given
situation. It helps if your RX has a good noise blanker (NB), passband
tuning, and a notch filter. Sometimes turning the AGC off will help dig
a really weak beacon out of the mud.

But a good synch detector WILL help with LW broadcast stations.


[email protected] December 4th 06 12:50 AM

sync detector for NDB/beacon hunting?
 

john wrote:
hi all,

will a sync detector buy me anything on LW???? i'm mostly into beacon
listening under 540 khz.

thanks, john


About the best thing I have found for NDB work is a good narrow
IF filter. One difinition of good to me is minimal leakage around
the filter. This leakage will allow the unwanted wider BW signals
around the filter. Defeating the whole idea of a better filter.

The InRad 1.8KHz SSB filter does ok,

A 500Hz CW filter does a better job, but you have to learn
how to tune in an AM signal in the SSB mode with a filter
that narrow.

Very touchy!

Sometimes USB is better, sometimes LSB.

A good steerable antenna is a must have. Really helps to null out
interference from either adjacent stations or from the omni-present
LF noise.

Terry


[email protected] December 4th 06 08:09 AM

sync detector for NDB/beacon hunting?
 

john wrote:
hi all,

will a sync detector buy me anything on LW???? i'm mostly into beacon
listening under 540 khz.

thanks, john


I vote for the narrow band filter. However, you could try a synch
detector listening to one sideband AND using a program like ARGO to
visually decode the beacon.

I use a 250Hz crystal filter with the radio in CW mode. This require
you to tune to the location of the sideband, not the carrier. Generally
I find the beacon in AM, then change to CW if needed.


Mark Zenier December 4th 06 05:29 PM

sync detector for NDB/beacon hunting?
 
In article . com,
john wrote:
hi all,

will a sync detector buy me anything on LW???? i'm mostly into beacon
listening under 540 khz.


If you've got a computer with a good sound card, look into those
spectrum analysis programs that the hams use for moon bounce work.
They use digital signal processing algorithms, like the Fast Fourier
Transform to get equivalent filter bandwidths in the 10s of Hz range.

Mark Zenier
Googleproofaddress(account:mzenier provider:eskimo domain:com)



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