Bill ha escrito:

Hello everyone I am looking for detailed plans for an AM loop. I will
be using it only for one frequency 1370AM so I dont want any tuners just a
simple AM Loop antenna for my AM radio. I will have to solder a 1/8 plug to
a 6-8 ft feedline to connect to my radio. It is a Kaito portable model
1103. I want to built this AM Loop cause I listen to talk radio alot and
the static and other distant stations sometimes make it hard. I have done
alot of looking around on google searches but have found no real detailed
plans I am not sure if I should go with edge wound or Spiral wound. Any
info you guys can give especially a detailed plan would be greatly
appreciated. or maybe there is a website I may not have seen you would like
to suggest. I am sure I have seen most of them atleast the most popular
ones. Anyways thanks in advance for any input Bill

Hello Bill,

Regarding your AM loop antenna.

Are you sure the external antenna socket also works for AM? You may
check this by inserting a plug without antenna. The ferrite antenna in
your radio will not be that bad.

You mentioned static and other distant stations. I am not sure whether
the loop will improve the reception. Has the signal from your favorite
radio station sufficient strength (on your current radio)?

Before you build, try to locate (with your current receiver) the best
place and orientation for your loop to be built. Do not use the
external adapter for this. If you cannot find a place/orientation with
good reception, a loop will not do much better.

If you found a good place, power your radio via the mains adapter. This
will clarify whether noise from the mains enters the ferrite antenna.
If so, the loop design must be such that noise does not reach the loop
via the cable between the loop and your receiver.

Generaly a loop will only help to overcome the radio's internal noise
(bad Sensitivity) and spurious products (generated by your receiver)
and interference from nearby sources (electronic equipment). The last
item only, when you can position your loop away from any interfering
source.

The loop will also not improve interference from a very strong adjacent
station. You may orient the loop to get a strong adjacent station into
a null, but this is possible with the built-in ferrite antenna too.

Regarding tuning.
With average means, a resonating (=tuned) loop can be made smaller and
better. When you use fixed capacitors for most of the required
capacitance, you may use a smaller (mica compression) trimmer capacitor
to do the fine tuning to your desired frequency.

I hope this will help you a bit.

Best regards,

Wim
PA3DJS