Longwave receiver

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ab2ms

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Looking for some input on good rx below 500Khz. I am primarily one of those weirdos that listen to the static trying to pull out a few NDB beeps and DGPS beacons (and whatever else I run into down there) and hope to get my hands on something with good sensitivity down there. I currently use an altoids tin special to bump the range up to the 10mhz ham band but am now hoping to get a separate radio. I am looking at an R75 but figured I'd get some opinions first. None of my HF rigs include the freqs down there, but probably wouldn't excel there anyway. I'm not looking to break the bank, but want somewhat decent performance. Thoughts? Suggestions?
 

raisindot

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Not really a suggestion but a question, since I've never really paid a lot of attention to LW before.

Anyway, I was tuning below 500KHz with my Sat 800 attached to an outside longwire, and, in addition to some beeps, I picked up a number of faintly intelligible audio signals. It seemed like some of them were the usual right wing stuff you get on SW, but at least one of them featured an announcer with a British accent.

Is it likely that there are transmissions in this band, or it is more likely that they are "ghosting" from a higher frequency? Would it be possible to pick up an overseas LW broadcast from my Boston-area location?

Note, a night later I listened to the same band with my JRC NRD 545 and couldn't pick up any of this stuff.

Suzie
 

ka3jjz

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It's quite possible it was both - it's not uncommon for mixing products from strong MW stations to get into the LW section It is absolutely possible to receive Euro broadcasts on LW with the right antenna and conditions. My LW friends tell me that it's common to have a filter in front of the receiver to block the MW out; but remember to disconnect it when you want to return to normal ops.

I don't remember whether the 545 has this - it might - but it's not uncommon for the sensitivity to be reduced below 1 mhz or so to make it less likely to overload. Someone (another 'basement dweller' as they're sometimes called) with a 545 that knows this for a fact one way or the other can comment.

I can't stress this enough - the Longwave Club of America specializes in topics just like these. If this is your bag, or you just want to learn more about LW antennas, techniques and so on, this is where you want to be. There are many hams there too, so don't feel shy if you have your ticket.

As a side note, I see someone wrote up something about the R75 performance in this band. Since this too is a popular topic here, it's worth reading if this is your radio.

73 Mike
 
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ab2ms

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The european AM broadcast band indeed lies down there. Sometimes you can even hear Iceland. Many signals lurking down there to be found :)
 

k9rzz

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Well, it's the Euro LW broadcast band. They also have an AM BCB with 9khz channel splits. I've used a number of radios down there and I find that once the local AM stations go to night power around sunset, I don't have any problems with images.
 

zz0468

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To the OP...

I'm using an ITT Mackay 3041A, and have found that it works substantially better down that low than even my IC-746PRO. You may want to hit eBay and see what's out there in the way of commercial grade receivers. It was once a multi-kilobuck receiver that I paid about $300 for, so there's some bargains to be had.
 

lanbergld

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The 2 best that I've used for longwave are the Icom IC-R75 and the Yaesu FRG-100. Both of those are sensitive in the low regions and have fine tuning resolution. But any receiver with tuning increments of 25 Hz (or less) will work, with a decent sized loop antenna. The loop does not have to be outdoors. Simple loops made of coax wire are pretty good.

Those VLF/LF upconverters are helpful for receivers that don't have good sensitivity below 500 kHz. Palomar discontinued production of their VLF/LF upconverter, but LF Engineering still sells one - the L-111. I use that one myself.


Larry Lanberg

Richmond VA
 
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va3saj

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Raisindot:

I wonder if your "announcer with a British accent" might have been the Longwave BBC Relay from Droitwich, in the UK? They put out a decent (500 kw) longwave relay of the BBC, and are sometimes audible after dark over here in Canada. So is RTE 1 Ireland. I sometimes hear them at night in winter but I'm using a fairly sensitive receiver (Kenwood TS850S). I find that for longwave, the main thing that matters is antenna length, length, length! I have several antennas here (verticals and others) but the only thing that really performs on longwave is a 150 foot dipole, which is about the limit I can do on my property. Longwave stations you can get in my location (Ontario, Canada) include:

162 Khz France Iter
171 Khz Medi 1 Morocco
183 Khz Europe 1, Feldsburg, Germany
198 Khz, BBC Droitwich, UK
216 Khz, Radio Monte Carlo
234 Khz RTL Luxembourg
252 Khz RTE Radio 1 Ireland

Julian
va3saj
 

k9rzz

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Well, if you're digging for NDB's think about a ham rig that has a nice tight CW filter. I love my FT767gx for that. I can set the tuning steps for 1khz (with or without the 400hz offset for the Canadians) and just run through the band. Sensitivity is great. The good 'ol R71a works great down on longwave and they don't cost much these days although you gotta start thinking about failing components on these older rigs.
 

zz0468

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Well, if you're digging for NDB's think about a ham rig that has a nice tight CW filter.
Lacking a tight filter, and there are a lot of excellent receivers that lack CW filters, one can use an external piece of software, such as Spectran. It not only will provide a narrow filter, it does noise reduction, and has the ability to show on the screen signals that are so far below the noise they're completely undetectable by ear - and the CW ID stands out like a sore thumb!

More than half of my NDB loggings were first spotted using Spectran because there was really nothing there to hear.
 

k9rzz

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Yes, good point.

My favorite has been "SR5", digital audio freeware for your computer with fully configurable filtering.

Link: ar5
 
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