Best wire for AM loop

mike65

I want to rig up a simple AM loop antenna, I could get some bog standard "bellwire". Does anyone have any suggestions for anything else that might get better results. Picking up a clean BBC 5live signal is my aim.

Fuzzy Clam

Bell wire should be perfect. I used 2.5 sq mains wire on my sw loop (simply because I've a ton of it here)
Are you going to use a variable capacitor?

mike65

Wha? :eek:

It'll be connected to standard AM "wrap-round" terminals on the receiver.

watty

The only "better" is thick bundle of Litz or insulated enamel wires or micro-bore copper tubing. Bit of an overkill.

The current mostly flows on the surface. For an Non-Transmitting external AM loop for "ext AE" terminals on broadcast radio, bell wire (or anything else) is just fine.

The larger the diameter it is the better, ie 1 or 2 turns of 2m diameter is far superior to 10 turns of 20cm diameter. We I was a kid we had a 90V battery valve radio with no ferrite rod. As was common from 1920s to 1950s it used about 20turns of enamel wire loop concealed in the lid side walls.

A 5.5m CB whip with loading coil in bases removed and replaced with about 80 turns on drain pipe in series on the chimney might work better. Or not, depending of typed of local interference

mike65

Cheers, hardware shoppe it is then.

Fuzzy Clam

mike65 wrote: »

Wha? :eek:

.

Presume this refers the variable cap?

One of these (approx 500pf, the type that can be found in an old radio) across the loop can be tuned to bring it into resonance.

watty

Yes.

Or short the two separate 200pFs of "polycon" variable cap tuner from €4 AM MW pocket radio together.

dxhound2005

mike65 wrote: »

I want to rig up a simple AM loop antenna, I could get some bog standard "bellwire". Does anyone have any suggestions for anything else that might get better results. Picking up a clean BBC 5live signal is my aim.

The trouble with 5live at least up here at the border is that the signals arrive from different transmitters in the North and GB at slightly different times causing distortion especially on 909. You have to keep moving a radio with an internal ferrite rod to counteract this and even with a loop you might find that this is still a problem. Did you ever try the transmitter in Wales on 990 kHz? Even though it is only 1 Kw it can give a cleaner signal.

Some portables have synchronous detection which can "iron out" the distortion or you can use upper or lower sideband if the radio has SSB to do the same. Or you can listen on your TV if you have satellite or on the internet.

mike65

693 is the best signal here, interestingly I used to get 990 quite well in my old works van but its not coming in at all at home. I should be able to listen on NTL FM analogue but thier feed to the Waterford cable system is and has always been flakey - its been nothing but a carrier wave for the last 10 days. Yes I did get in touch but they seem not to care a jot. Internet is fine to a point (downloads) and Skybox is grand if in living room but I always listen to the game drinking coffee lying on the bed or in front of the interweb.

Fuzzy Clam

http://www.xs4all.nl/~pa3dlp/middengolf.htm

Shows how the cap is connected.