MW: Local class D station still broadcasting at midnight

[ur20v]

As a creature of habit, I tune over to 1030 WBZ to fall asleep, like I always do. But the semi-local class D Spanish station is still broadcasting at full power, several hours after sunset! A disappointing ending to a very disappointing day.

 

[fleef]

There's a way to cancel them out, but the DIY instructions were on another computer. It's *not* using a tuned loop, it's a DIY deal, using tin foil, a wire to the receiving antx on your radio, and moving the radio directional to the station. I'm too busy right now to find the link again- forgot the proper search terms. IF I remember this tomorrow, I will search again for the how-to- it's a very old post, wish me luck. Has to do with blocking out another MW station- my searches right now come up bupkis- no time tonight to do so any more and it's late

I know your pain. Apparently the Mexican stations don't respect the FCC... it bugs me when I am dxing and my late night listening on MW.

 

[N9PBD]

As a creature of habit, I tune over to 1030 WBZ to fall asleep, like I always do. But the semi-local class D Spanish station is still broadcasting at full power, several hours after sunset! A disappointing ending to a very disappointing day.

You might try this: https://www.fcc.gov/research-reports/guides/broadcast-complaints

I think the FCC actually takes action against broadcast licensees.

 

[WA8ZTZ]

WBZ puts a good signal in here (have even received it on my xtal set) in the evening after the local 5kw daytimer signs off.
Occasionally tune in to catch Dan Rea's Night Side program.

 

[Lauri-CoyoteFrostbite]

There are ways to filter out one MW station to hear another. What your thinking of are phased antennas to null out the offender. Here is a site that *claims* a product, and the theory behind it.... I make no endorsements...
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Antenna phasing makes a difference -- antenna lab on hard-core-dx.com
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[ridgescan]

Yes. I suffer the same thing here in San Francisco. I enjoy 920kHz out of Modesto at bedtime with their oldies, but the local station on 910kHz bleeds in especially during commercials. With my two bedside DXrs, my sx-88 with its bandwidth selector, and my Realistic DX-160 with its awesome selectivity on MW, both with antenna trimmers that I can use to weaken adjacent power, I can get a manageable copy.
There's another station I like a lot out of Ventura, Ca. on 1520kHz, but the same bleedover from a local Asian station on 1510.

It seems like certain stations are immune to power-down.

 

[a29zuk]

The MFJ-1025, out of the box, only works down to 1.8 mhz. Have done the modifications on it to work down on the broadcast band. It works well for nulling unwanted stations.
Ridge, you could do the same with your Timewave without any modifications.

Jim

 

[ridgescan]

The MFJ-1025, out of the box, only works down to 1.8 mhz. Have done the modifications on it to work down on the broadcast band. It works well for nulling unwanted stations.
Ridge, you could do the same with your Timewave without any modifications.

Jim

Jim thanks for this. I read in the instructions about enabling MW notch via internal jumpers, but how do I use the unit for adjacent interference? Could you kindly enlighten me? Just a mere manipulation of controls?

 

[WA8ZTZ]

Yes. I suffer the same thing here in San Francisco. I enjoy 920kHz out of Modesto at bedtime with their oldies, but the local station on 910kHz bleeds in especially during commercials. With my two bedside DXrs, my sx-88 with its bandwidth selector, and my Realistic DX-160 with its awesome selectivity on MW, both with antenna trimmers that I can use to weaken adjacent power, I can get a manageable copy.
There's another station I like a lot out of Ventura, Ca. on 1520kHz, but the same bleedover from a local Asian station on 1510.

It seems like certain stations are immune to power-down.

That station on 910 may be running IBOC.
If it is, all the selectivity in the world isn't going to help.

Have the MFJ 1026 here (did the LW/MW mods) and it does help cancelling out unwanted stations and noise. It will only cancel out one other undesired signal. If, for example, the noise is from multiple sources... forget about it. The controls require some manipulation to get good results. The key seems to be to adjust the respective gain controls to get the desired signal on the main antenna and the undesired signal on the "noise" antenna at the same strength and then adjust the phase control for null.

If the undesired stations are on enough different azimuth your loop should be able to null them out.

 

[ridgescan]

That station on 910 may be running IBOC.
If it is, all the selectivity in the world isn't going to help.

Have the MFJ 1026 here (did the LW/MW mods) and it does help cancelling out unwanted stations and noise. It will only cancel out one other undesired signal. If, for example, the noise is from multiple sources... forget about it. The controls require some manipulation to get good results. The key seems to be to adjust the respective gain controls to get the desired signal on the main antenna and the undesired signal on the "noise" antenna at the same strength and then adjust the phase control for null.

If the undesired stations are on enough different azimuth your loop should be able to null them out.

Thanks for the help! Is IBOC where there are "rushing" sounds on either side of their frequency? If so, no, 910 doesn't use that. The only station I know of that does have that characteristic is a sports station on 1050. I gave the Timewave a go last night after reading Jim's post, but on the R71A at the desk and it did seem to cut about half the bleedover. The only small problem is I listen to those stations at bedside with one of the other two receivers and I'd have to jump up out of bed to adjust the Timewave any time I changed frequencies. OTOH I could just stick to one frequency
And you are right about the loop-it surely does help with null.

 

[WA8ZTZ]

Thanks for the help! Is IBOC where there are "rushing" sounds on either side of their frequency? If so, no, 910 doesn't use that. The only station I know of that does have that characteristic is a sports station on 1050. I gave the Timewave a go last night after reading Jim's post, but on the R71A at the desk and it did seem to cut about half the bleedover. The only small problem is I listen to those stations at bedside with one of the other two receivers and I'd have to jump up out of bed to adjust the Timewave any time I changed frequencies. OTOH I could just stick to one frequency
And you are right about the loop-it surely does help with null.

Yes it does make sort of a "rushing" hash of the adjacent frequencies. The station on 1050 may or may not be using IBOC all the time according to various sources. If you have a SDR it is plain to see in the waterfall out +/- 15 kc from the carrier freq.

Maybe a small homebrew box loop or the Grundig AN 200 loop for the bedside receivers.
Have both here and they do work. The AN 200 has the advantage of being tunable plus it comes with a cable that allows it to be wired direct to the RX.

 

[ridgescan]

Nah I do ok with those receivers especially the SX-88, I just switch the band width knob to 5kHz and it kills all the bleedover. The DX-160 is trickier-I adjust ant. trimmer for weak instead of peak, then tune a little away from the local flamer on that one. Plus that old 160 really is very selective in MW.

 

[WA8ZTZ]

Ridge,

Another idea... if necessary, your CCrane twin-coil may be useful in nulling out the bleedover from the local flamethrowers.

 

[a29zuk]

Nah I do ok with those receivers especially the SX-88, I just switch the band width knob to 5kHz and it kills all the bleedover. The DX-160 is trickier-I adjust ant. trimmer for weak instead of peak, then tune a little away from the local flamer on that one. Plus that old 160 really is very selective in MW.

The DX 160 was my first communications receiver. I also enjoyed listening to MW on it, too, as like you noted, had good selectivity.

Jim


Sent from my standard laptop with a standard keyboard.

 

[a29zuk]

That station on 910 may be running IBOC.
If it is, all the selectivity in the world isn't going to help.

Have the MFJ 1026 here (did the LW/MW mods) and it does help cancelling out unwanted stations and noise. It will only cancel out one other undesired signal. If, for example, the noise is from multiple sources... forget about it. The controls require some manipulation to get good results. The key seems to be to adjust the respective gain controls to get the desired signal on the main antenna and the undesired signal on the "noise" antenna at the same strength and then adjust the phase control for null.

If the undesired stations are on enough different azimuth your loop should be able to null them out.

Also, experimenting with your main and noise antennas with have a effect on nulling.
Currently mine are only fed about two feet apart but one runs east/west and the other north/south.
Like WA8ZTZ says, if the two stations are coming from the same direction it will not work.
Would like to take the Palstar and the MFJ out to the park sometime and experiment with longer wire antennas.

Jim


Sent from my standard laptop with a standard keyboard.

 

[ridgescan]

I have the twin coil semi-permanently attached to the internal coil on my Korting Delmonico out in the kitchen. That radio is a fun MW DXr too but it aint near the bed
In my first post in post #6 here I guess I only meant to relate with the OP about having to deal with adjacent bleedover, but I did state from there on that I can deal with it via attributes on my two bedside rigs as well as now what you all suggested thereafter that I will try, for which I thank you
It's funny, I get three oldies music stations among 5 or 6, long distance, that are parked next to local flamers; 920 out of Modesto, 1250 out of Willits, and 1520 out of Ventura-so I guess I was sort of feeling the OP's pain when I first posted

 

[WA8ZTZ]

Would like to take the Palstar and the MFJ out to the park sometime and experiment with longer wire antennas.

Good idea... get away from all the noise.

Find a suitable spot and simply lay as much wire as you can right on the ground. The longer the better.
Aim the end of the wire in the direction you want to DX.

See post #5, click on the link to "hard-core DX" and then in that article click on the link "MFJ needs to be modified" for some mini-DXpedition ideas.

 

[a29zuk]

Good idea... get away from all the noise.

Find a suitable spot and simply lay as much wire as you can right on the ground. The longer the better.
Aim the end of the wire in the direction you want to DX.

See post #5, click on the link to "hard-core DX" and then in that article click on the link "MFJ needs to be modified" for some mini-DXpedition ideas.

I have taken the Palstar and hundreds of feet of wire to the park several times in the past with great results.
But I haven't taken the MFJ out yet and experimented with two antennas. If we keep getting this dry weather the mosquitos will be non-existant. That is half of the battle. The dog has fun, too!

Jim

 

[WA8ZTZ]

But I haven't taken the MFJ out yet and experimented with two antennas.

Jim,

Be sure to check the links to the article referred to in my last post (regarding Lauri's post #5).
It was written by Mark Connelly who has done lots of AM BCB DXing and written a bunch of good tech about it.
There is also a guy on here, also in Michigan, who goes by Kilokat7 who has done amazing AM BCB DX with phased antennas.

 

[KC4RAF]

In reference to IBOC being run on the AM stations state side, here's a site that list those AM broadcasters:

AM IBOC Stations on the Air

I have no idea how accurate the list is. But it may help some one with bleed over.