Failed AM loop

[fmdxer1]

I just built a 2-ft loop, I followed instructions (I thought) from a web site. Wasted a whole evening. It dont work. Any important tips or suggestions?:banghead:

[cd637299]

I am not an AM loop expert, nor do I play one on TV.

However, were there supposed to be capacitors in the unit? Also, what is the AM radio? Does it have terminals in the back, or is it one of those place-it-close-to-the-radio (e.g. Select-a-Tenna) loops?

I myself have pretty much ditched AM DXing here, mainly due to (1) wayyyyyyyyyyyy too many stations at night, and (2) a horrible buzz on some parts of the dial. I even complained to the power co. about it, and they really didn't help much. (My AM radios are usually 8' from the PC, so it cannot be the computer's fault.)

cd

[fmdxer1]

I took the capacitor from an old am transistor radio and it is one of those place-it-near-the-radio types.

[mrhoover]

really didn't help much. (My AM radios are usually 8' from the PC, so it cannot be the computer's fault.)
cd

It certainly could be,if I want to AM DX the PC is switched off,causes far too much interference for comfort anywhere in the house!!

Simple test...Listen to the AM band with/without the PC on and note the difference.For the test as well as the pc being "off" remove the mains supply from the pc.

LCD and Plasma TV's also cause a lot of interference.Do a similar test.

Hugh

[Russ-PA]

It might help to know what kind of a loop it is - without that it's hard to determine what might be wrong. My first guess would be to check to see if you hooked up the capacitor properly. How many terminals does the capacitor have to connect to, and are they only on one side or two sides ?

[Mike-CT]

Your coax goes to the single turn in the center of a box loop. The capacitor goes to both ends of the other 17 or so turns on either side of the single turn. Put a portable inside the loop and tune the loop and the signal level on your portable should jump drastically. This is, of course, assuming you've built a box loop. Email me if you're stuck because I've built a few and have a 2 ft loop in the basement right now.

[John Wilke K9RZZ]

Also, re-check your wire length. It may be working, but not where you're trying to listen.

Help us - help you:

- which plans are you following?
- what radio are you using?
- photos get extra points!

[fmdxer1]

Thanks for all the help and troubleshooting guys. I got it working just the other day. It kept nagging at me so I got the capacitor from another radio and come to find out the problem must've been with that first capacitor - or I had it wired up wrong.

As far as performance goes - I was unimpressed as it only slightly increased signal strength of any station. Another annoyance was the bleed from a couple local AM'ers that was showing up everywhere on the dial.

The radios used for my first loop "test" was a CCRadio and a Grundig G5. Grundig performed better but had the most "local splatters" on various freq's.

For the antenna I used 120 feet of 20 gauge bell wire that was about 17 turns. Perhaps I had my hopes up too high for the loop. Daytime enhancement was slightly noted as I said but at night I could tell no difference.

[Russ-PA]

Although that's a bit smaller wire than normally used for a tuned loop, the length and number of turns are in the right ballpark. But it still should perform better than your description. Does tuning the capacitor produce a strong peak on a channel with a weak station ? When tuned to a strong station, does rotating the loop produce a noticeable null ?

If either one of these doesn't happen when you put a radio in close proximity to the loop, there's another problem.

Mine has been in use since 1970. It uses #16 stranded wire, 19 turns using 2' diagonals.

[John Wilke K9RZZ]

You could probably tweak it a bit by leaving a 1 wire width space, or more, between the windings. That reduces the inter winding capacitance and improves the Q or sharpness if the tuning. It looks like you've got enough space there on your supports.

[Fred-OH]

I just built a 2-ft loop, I followed instructions (I thought) from a web site. Wasted a whole evening. It dont work. Any important tips or suggestions?:banghead:

Where does it resonate? Can you get a peak on 150-550 or 1700-6000?

I'm assuming that this is just your standard loop with a coil and capacitor in parallel.