RadioBanter - View Single Post - Shortwave Antenna OverLoad - Urban Legend or a sad reality for some . . . What Do I Do ?

January 23rd 05, 05:34 AM

wrote:

I have 2 R2000s and a DX398. Radios not known for their wide
danamic range. I use a ~70' wire antenna, with a 9:1 tranformer,
(with another 1:1 for ground noise isolation) and I have very little
problem with overload. A ham who operates at(or beyond) legal
power lives about 2 miles form me and when he fires up, I do
have to leave the band he is operating on. But I used to own a
R390/URR and a R392/URR and both suffered the same problem.
I borrowed a R5000, and a PCR1000 and the R5000 was
slightly better. The PCR1000 was a POS joke. The DSP was nice,
but I guess I'm a "horse drawn man", and a radio must have knobs.
My Heath GR64 doesn't have any overload issuses, but given it
is a deaf as a post, I am not shocked.

I supect that with a decent antenna, a good matching overload
maybe on over blown issue.

Terry

As I understand it, it is the front end transistor(s) that are being
overloaded when somebody talks about "antenna overload". This problem
occurs mostly with cheap portables. Since they are built cheaply, the
front ends are also cheap and do not have the selectivity of a better
quality receiver. Clipping a length of wire to the whip of one of these
portables will pick up images mostly of AM and FM stations that are in
the vicinity of the receiver. For example, I have a cheap Radio Shack
AM/FM radio that is easily overloaded. Just pointing the whip antenna in
the direction of the nearest FM station (about two miles away) is
sufficient to produce images of that station all over the dial. The
problem is not with the whip, it is the front end.