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Old December 31st 06, 01:46 AM posted to rec.radio.amateur.antenna
J. Mc Laughlin J. Mc Laughlin is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 172
Default Delta Loop Ideas Please

Dear John in UK (no call sign):

Five bands (14, 18, 21, 24, 29 MHz?) with one transmission line shouts
for the use of a LDPA. You can construct one that will work using
information in the ARRL Antenna Book or several other references.

Prof. Cebik has a number of notes on this type of antenna
(www.cebik.com). A good place to start is:
http://www.cebik.com/lpda/lpd.html

A Michigan company that I understand has dealers in UK, is Tennadyne.
http://www.tennadyne.com/index.html
They make good quality, simple LPDAs. I have no connection to the firm.

Successfully nesting five tightly coupled antennas is a very difficult
task. A LPDA will work.

73 Mac N8TT

--
J. Mc Laughlin; Michigan U.S.A.
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"John" wrote in message
...
I have been researching for a while now around the area of nested delta
loops. I want to upgrade my multi-band vertical antenna with delta loops,
each one resonant to cover 20 to 10m. However there is nothing on the
internet about nested delta loops. My wish is to have the delta loops
orientated such that they are pointed at the top and fed one third of the
way up one of the vertical sides to get a low angle of radiation.

I realise that they have an impedance of around 100 Ohms and this would

need
to be matched. The usual method of doing this is to use a quarter wave
length of 75R coax to match to 50R.

Much in the same way that parallel dipoles can be fed with a common

feeder,
can 5 delta loops be fed via coax matching stubs with a common 50R feeder?
(i.e. bring the ends of the matching stubs together?).

I tried in the summer to nest 5 delta loops with the feed point as

described
above and then brought the feed points together (without matching stubs) ,
however it is not physically possible to do this - they really need
separating out.

Any ideas any one? My basic aim is to have 5 resonant antennas with no
tuning unit involved.

Thanks

John