I would like to know what kinds of results you are obtaining with your antenna/receiver setup (separating strong local stations from DX stations on adjacent frequencies), particularly if you are located close to an urbanized area with a lot of strong signals. I'm debating in my mind to build a box loop, but before I do, I would like to know what other options there are. (Yeah, I know about going on a DXpedition, sure, I'd love to!)
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Best antenna for AM DX being close to a metro area with a lot of strong signals
- Thread starter stormy01
- Start date
R
rbrucecarter5
Guest
Re: Best antenna for AM DX being close to a metro area with a lot of strong sign
I used a 4 foot box loop to listen to WBBM 780 Chicago in the daytime from Lubbock, TX, which has a strong local 790 KFYO. I repeated this feat many times at different times of the year using various large box loop designs. Receiver was a GE Superadio 3. WBBM ID's and programming was clearly audible, even though there was a little splatter from KFYO. The Q of the box loop definitely helped reject the local and put gain on 780 instead.
stormy01 said:
I used a 4 foot box loop to listen to WBBM 780 Chicago in the daytime from Lubbock, TX, which has a strong local 790 KFYO. I repeated this feat many times at different times of the year using various large box loop designs. Receiver was a GE Superadio 3. WBBM ID's and programming was clearly audible, even though there was a little splatter from KFYO. The Q of the box loop definitely helped reject the local and put gain on 780 instead.
Try a loose-coupler loop. You make the loop on a frame with enough wire to reasonate and tune with a standard 365pf variable cap.
Both ends of this loop conect to the cap. Set it up so the "outer loop" can rotate upon a vertical post. Align the antenna with the station you want to receive.
A smaller loop, of maybe 15 feet of wire is mounted on the vertical shaft the main loop is on. The inner loop need not be able to rotate, but the stand the whole thing is mounted on should be able to. It is important to be able to vary the angle between the inner and outer loop. The 2 ends of that inner loop are connected to the antenna and ground connections for AM, if your radio provides these. Then, the amount of pickup can be varied by changing the angle of the inner-to-outer loop. The phase of one loop to the other can either aid or oppose the reception of signals, one way adds, the other way subtracts from the the signal coupled in from the outer loop. You tune the outer loop by angle and using the variable capacitor.
If you radio has only an internal loop, you can wrap 5-6 turns of wire around the outside of the radio, and connect that loop to the wires of the inner "pickup" loop. If you do this, you can also use the position of the radio to aid/oppose pickup or null unwanted signals in addition to aiming the outer/inner loops to null unwanted signals.
You can then also connect a longwire to the inner or outer loops, and find many combinations of amazing gain/rejection.
The Q of such an antenna makes for wonderful analog reception, but results in supressing sidebands too much for HD reception.
The bandwidth is much too narrow for it to help with iboc signals. The broadbanded loop such radios come with doesn't have much
pickup, but the the low-Q, with broader bandwidth is important for HD reception.
Are you trying to dx a nearby HD AM station?
Or "real" AM radio?
Both ends of this loop conect to the cap. Set it up so the "outer loop" can rotate upon a vertical post. Align the antenna with the station you want to receive.
A smaller loop, of maybe 15 feet of wire is mounted on the vertical shaft the main loop is on. The inner loop need not be able to rotate, but the stand the whole thing is mounted on should be able to. It is important to be able to vary the angle between the inner and outer loop. The 2 ends of that inner loop are connected to the antenna and ground connections for AM, if your radio provides these. Then, the amount of pickup can be varied by changing the angle of the inner-to-outer loop. The phase of one loop to the other can either aid or oppose the reception of signals, one way adds, the other way subtracts from the the signal coupled in from the outer loop. You tune the outer loop by angle and using the variable capacitor.
If you radio has only an internal loop, you can wrap 5-6 turns of wire around the outside of the radio, and connect that loop to the wires of the inner "pickup" loop. If you do this, you can also use the position of the radio to aid/oppose pickup or null unwanted signals in addition to aiming the outer/inner loops to null unwanted signals.
You can then also connect a longwire to the inner or outer loops, and find many combinations of amazing gain/rejection.
The Q of such an antenna makes for wonderful analog reception, but results in supressing sidebands too much for HD reception.
The bandwidth is much too narrow for it to help with iboc signals. The broadbanded loop such radios come with doesn't have much
pickup, but the the low-Q, with broader bandwidth is important for HD reception.
Are you trying to dx a nearby HD AM station?
Or "real" AM radio?- Status