HFU HF Underground
Loggings => MW Loggings => Topic started by: Dxer92 on December 14, 2015, 2221 UTC
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Hey everyone, I get absolute terrible reception on my 10/11 meter antenna (Antron 99) but only on the lower bands in which i know why my antenna is not fitted for these frequencies. But I also get a terrible noise and it does sound like Power Line Noise how do I reduce that noise? (Yes my Radio and Antenna is grounded.) Also, what kind of home brew simple MW antennas can i make to get better reception on the MW band? Yes, I will even consider buying one if there are any.
The radio that i'm using is a Icom 718, my antenna does pretty good on SWL but i know the MW band isn't going to be that great. If anyone could help that would be great.
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Best is a loop, many designs out there, here's one;
http://www.hard-core-dx.com/nordicdx/antenna/loop/hulaloop.html
Otherwise just use a 'Long Wire' antenna, bit noisy tho'.
Str.
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Yes, Loops are the way to go on MW. Next in line would be any type of LARGE closed loop antenna. The smaller loops give you some nice directional characteristics and are more immune to noise.
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The above suggestions are all good. I will add a few more.
You can find more info about these at http://www.ve1zac.com/My%20Receive%20Antenna%20Compendium.htm (http://www.ve1zac.com/My%20Receive%20Antenna%20Compendium.htm)
or googling any of these can give you several weeks/months of reading material....
If you have the room, a 500' to 800' beverage is hard to beat, they can be unidirectional, bidirectional, reversible and can be electrically rotated a few degrees, but not rotatable like a magnetic loop.
Terminated Vertical Delta Loop and the various mutations (K9AY, pennant, Kaz, DKaz, SuperKaz). These are terminated with a resistor, giving a very nice directional pattern, and if you don't have room for a beverage, these give the best bang for the buck.
A pair of short phased verticals. [I have not tried these YET]
A BOG (beverage on ground) or LOG (loop on ground). [very simple and not bad performance]
For any of these antennas, it is best to locate them away from your house to minimize noise getting into the antenna system. I recommend a choke balun near the antenna to keep noise from traveling out to the antenna on your coaxial cable.
Your Antron99 should give decent reception on the MW bands if you have a pre-amp.
Maybe you have a balun in line that does not pass MW signals through it, or maybe a bad connector or cable.
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Dxer92,
a nice overview can also be found here:
http://www.n4lcd.com/wireantennas/
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I've used both BOG's and LOG's. I prefer BOG's as I find LOG's need a bit of amplification.
The first loop I built was the Radio Nederlands 1 meter MW Loop. It's easy to adapt to a PVC frame and works well. The old 365 pF variable caps the thing uses are getting hard to find but Antique Electronic Supply still sells them. You can screw around with the turns and get them to work up to the funny band, but it's a trial and error thing.
The best tropical band dx I ever got was with one of the modified versions, Bangla Betar over the pole on 60 meters with a clear id just after sunrise one spring morning. It was killer on the New Guinea stations on 90 meters, too.
A rotten cat took it out one day. Both loop and the cat are long gone, but I still miss that loop. Come to think of it that cat also took out an old Hallicrafters SX-120. Too bad it didn't take the cat with it.
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I get caps here:
http://www.midnightscience.com/
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That's about 3 bucks cheaper than AES. Nice find, Joe. Thanks!
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Thanks, PM. I buy all my caps there; they are friendly and quick delivery. The caps are good quality, and I believe they are made by Oren Elliot.
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If your radio is decently grounded, try using only the center conductor from the A99 coaxial feedline. Simply unscrew the PL-259 at the radio, and slide it out just enough to disconnect the outer shell of the connector.
Actual technical aspects aside, you now have a 18' vertical "longwire" instead of a tuned 11m vertical end-fed. YMMV on noise ingress, as the coaxial feedline is no longer acting as shielded coax.
Antenna aside, does the 718 attenuate the MW BCB band? Some HF rigs do, thus potentially needing a mod and/or additional pre-amplification.
I am not really into MW BCB listening, but even my lowly 9' ground-mounted vertical in the backyard can receive lots of stations when used with a ~20dB preamp. It has a mere four 9' ground radials and fed with RG-6QS. Feedline loss can be rather trivial for reception at MW, so the preamp is inside. Techically, I am not going go call it an active e-field/voltage probe antenna, but some perhaps would at such low frequencies when using a preamp. Anyway....
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Yeah actually the Icom 718 does have a built in Pre Amp, I'll have to try the just connector on the coax I never thought of that. And I'll check out the other loops too, thanks guys for your help!!
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And forgot to add in, my radio is grounded pretty well.
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And yes my radio does ATT on AM!! Why will that help with noise and reception?
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Stops the front end overloading!
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Yeah for some reason I can't get the screw part of the coax off to use just the middle conductor for the radio. That's what I get for buying RadioShack coax.
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Also here is another question, I did a random wire test today and actually the Antron 99 performed so much better then the long wire antenna. Not as noisy!!! Ok so here's the question lol, what can I do to make the reception even better on my Antron? RF Tuners, additional ground plane kit etc?
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Also here is another question, I did a random wire test today and actually the Antron 99 performed so much better then the long wire antenna. Not as noisy!!! Ok so here's the question lol, what can I do to make the reception even better on my Antron? RF Tuners, additional ground plane kit etc?
Phase it against another one to steer nulls.
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Why not just put up a balanced dipole, the simplest of antennas.
Your trying to use a CB antenna, why ??? you're not listening to CB!
Just put up a 'Proper' antenna, you will save a lot of time!
;D
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As noted, your HF rig attenuates MW so help with front-end overload from nearby commercial broadcasters, especially for 160m band reception, as that amateur band is right above the MW broadcast band. If operating at 160m, you ideally want to hear other amateurs instead of splatter from nearby AM broadcasters. ;)
The reason the A99 sounds "better" (probably more like less noise, right?) at MW is because of its dramatically compromised efficiency at such low frequencies.
Your A99 has a significant matching section, as it is basically a 1/2-wave, end-fed vertical dipole for upper-HF. Forget a tuner, too, IMO. In a pinch, the A99 can go down to the 15m amateur band with reduced efficiency via a decent antenna tuner, but it really drops off below there. It is a decent antenna for 11m CB, plus even the 10m and 12m amateur bands with a quick adjustment of the antenna's tuning rings. It is way out of tuning for MW, or to be straightforward, actually for pretty much any frequency below the 12m amateur band.
About the "random" wire, there are numerous variables involved in the performance: resonance, impedance, RFI ingress, etc. Noise can be an issue with simpl longwire antennas, especially due to common-mode coupling from the feedline. A 9:1 balun (or other ratio depending upon wire length) could help with noise, plus improve impedance matching.
Being realistic, any seriously widebanded HF antenna typically is a compromise, again for numerous variables. If you are looking for an off-the-shelf MW/HF receiving solution with a moderate footprint and a simple end-point feed, consider taking a look at the basic Par EF-SWL. That said, a balanced antenna, like a fan dipole (for your bands of interest) or a large horizontal loop would be even better IMO. A good start for more antenna ideas, and even more so if you do not mind building your own wire antennas:
http://www.hamuniverse.com/antennas.html
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Good morning! I have used and have 4 square, k9ay, and beverages. I have tried BOGs and Pennants. I also have Pixel Loop and good old dipoles. BOGs are easy to set up and work great. 200 feet is the optimum length. You can buy the transformers and terminations from dx engineering, as well as the wire. What I like about them is the simplicity. Just put them on the ground. That said, I spent the weekend building what is called a Misek micro SWA antenna. It is basically two beverages back to back fed in the center and phased with a variable phasor. Total length is about 60 feet. The antenna is amazing. You can steer a null through 365 degrees. This morning I was listening to CIAO on 530 and nulled it by 30dB and picked up another station on 530 (unid spanish and music). For such a small antenna is is really good. The version I implemented was designed by Dr. Lankford. He compared its performance to two phased verticals and said it performed just as well. You could make it longer and probably get even better performance.
Also try two long wires at 90 degrees phased through a variable phasor.
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Another place with good info on loops and wires:
http://www.wa2ooo.com