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Technical Topics => Equipment => Topic started by: DOCTOR on October 23, 2011, 2158 UTC

Title: longwave rcvr
Post by: DOCTOR on October 23, 2011, 2158 UTC
What would be a not to expensive longwave rcvr for beacons 540khz and below..I believe rat shack made a table top shortwave rcvr at one time which had air craft band on it forbeacons..
DOCTOR
Title: Re: longwave rcvr
Post by: cmradio on October 23, 2011, 2250 UTC
Hi,

I've tried over a dozen LW receivers from the DX[xxx] series from Radio Shack tohomebrew to the Grundig's and now have an Eton E5. With a decent antenna (like a nice big loop), it really doesn't matter sensitivity wise, it's selectivity you want there.

Fortunately, any good SSB with a narrow IF filter will do wonders, because the aero/marine NDP's are really loose tolerance on the 400Hz (Canuck) or 1KHz (US/most of the world) tone and you can zero-beat most unwanted ones in a pileup.

Fow longwave sensitivity of eveything I tried, the old DX200 won hands down. But being a simple circuit, overload, AM interference and selectivity sucked bigtime. I had to make a 9-pole LPF just to keep the AM out on that one.

The worst was the DX300/302. Specs are a complete lie... I lived right beside a military base and had volts per metre of CKN on 133KHz floating through the house.... if I made a renonant loop, I could light a small flourescent bulb in it. Pfffft! S-8 on the DX30x? C'mon!!!! Overload/IF was pretty good though - CKN didn't swamp it where a Satellit 800 was frackin' useless and had to be returned.

Unless you go to one of the ollllld rigs specifically designed for military coms or a LF AC voltmeter (those are great) on Ebay, I'd check any little portable and concentrate on antenna, antenna, antenna.

My twonie....

Peace!
Title: Re: longwave rcvr
Post by: The Hokie on October 24, 2011, 1805 UTC
What would be a not to expensive longwave rcvr for beacons 540khz and below..I believe rat shack made a table top shortwave rcvr at one time which had air craft band on it forbeacons..
DOCTOR

May be interesting to look at for LF reception: http://www.arrl.org/files/file/Technology/tis/info/pdf/0109031.pdf
Title: Re: longwave rcvr
Post by: cmradio on October 24, 2011, 2223 UTC
Have you also checked out these guys?

http://www.lwca.org

Cheers!
Title: Re: longwave rcvr
Post by: Zoidberg on October 25, 2011, 0527 UTC
I've been able to pick up local (Dallas Love Field airport) and regional (Gulf Coast) LW beacons with my Sony ICF-2010 and Magnavox D2935 portables using the internal loopsticks.  The main challenge is always local RFI.  No problems with the local MW flamethrowers like WBAP on 820 breaking through, as long as I use only the internal loopstick.  If I can get at least 50 yards away from nearby buildings and power lines I can pick up LW beacons when conditions are good.

My Palstar R30C is also excellent for LW with the right antenna, but only if I get away from suburban RFI.  Pricey just for that purpose, though, so I mainly use the Palstar for SWL.
Title: Re: longwave rcvr
Post by: DOCTOR on October 25, 2011, 2144 UTC
THANKS GUYS
I have a TESCUN PL600..Picks up a few beacons but that is it..
DOCTOR
Title: Re: longwave rcvr
Post by: Pigmeat on October 26, 2011, 1435 UTC
A lot of boatanchors from the 50's and 60's have good LW sections. Do a little research and hit the local hamfests. Old transmitters are usually overpriced,but you can still walk away with a steal on an old receiver.