Dear Flam,
You wrote on the 6th Nov 2009.
I read on the internet that adding "turns" to the Loop could improve signal
strength ?
The following was posted by me on the K9AY Groups (digest no 78) back in
late 2000.
"Hi K9AYers,
Tracey finally "brow beat" me to experimenting with some loop configurations
suggested by Johan Bodin a few months ago. Without going into lengthy
detail, one configuration consisted of two loops mounted at right angles
connected in series. To my surprise I measured a 5/6dB increase in gain over
the normal K9AY config. As a co-incidence, an e-mail from Gary was forward
to me, giving details of a 6dB increase gain using a two turn loop with a
resistive plus reactive termination. Therefore, I had to see if a single
loop of two turns would work for LW and MW with just resistive termination.
Well as far as I can see, the answer is yes, but only if the turns are
separated to reduce mutual coupling i.e. using a twin lead wire loop connect
in series only provides about a 2 dB gain increase. Separating the delta
loops by 1m at each end of the loop i.e. two poles at each end. The loops
cross at the apex. This provided the 5/6dB gain increase.
I would be interested in hearing from other users if my findings can be
replicated.
The only reason I can explain for this increase in gain is that the 450-50
match xmfr is not optimised for LW/MW. Hence raising the antenna impedance
with two turn loop provides a better Match! So the experimentation
continues!!!"
I don't have any more information on this 2 turn configuration.
73
Andy
_______________________________________________
Antennaware mailing list
Antennaware@contesting.com
http://lists.contesting.com/mailman/listinfo/antennaware
|