[RFI] Antenna Tonna producing RFI?

[Sérgio Moura de Sousa]

Greetings!

I am writing this new topic, because I have a problem and would
apreciate if some of you more experienced R. Amateurs could help me..

My regular radio is an Icom IC-706MKIIG that I use as a base radio
with a Lunar 160P amplifier and a Tonna F9FP 9 elements yagi antena
for 2 meters.

The reason why I am writing was because last week, I was doing some
FSK441 with a friend in England, and a neighbor come to my house
complaining about interference in his TV. Sad...

After that i began doing some tests at my house, directed the antenna
to my tv aerial antenna and had to admit one of the channels (channel
is on UHF) gets completely mad if I use more than 25W...

This only happens from 144.000 to 145.000, and I was told it is the
3rd harmonic of 144.300... from 145.000 to 145.800 I dont get any
problems at whatever wattage I use.

After detecting the problem, I started wondering what was producing
these harmonics...

Tested Icom + Amp ----> Harmonics

Tested Icom only -----> Harmonics

Tested Yaesu Vx-150 + Amp -----> Harmonics

Switched the cable (RG-213) from radio do antena, and both PL
conectors, and everything was the same.
Tried this with a home made 5 ele. yagi, and had no RFI. Neither with
a homemade 5/8 vertical antenna.

I have to say the problem must be on the antenna.... Since I bought it
used, it has no warranty, and I dont know what I can do.

A ham friend of mine told me to try a RFI filter between transceiver
and cable to antenna, that it should work.

My question is: Since the problem is in the antenna, do you think this
could work?

If not, and if you know those kind of antenna, what could be wrong
with it? It is almost new, and seem to be in perfect order... Could
the problem be in the dipole? The N conector on the antenna is covered
with plastic, and to open that part I would had to brake it apart...


Thank you so much for your help and answers to my several questions Smile

Sergio