"Wilbur Hubbard" wrote in message
anews.com...
"Lloyd Bonafide" wrote in message
...
"Wilbur Hubbard" wrote in message
anews.com...
"Hanz" wrote in message
...
Can I use the 735 without the antenna tuner to only receive signals (no
transmission)? What happens if I key the mike without the antenna
tuner?
Thanx.
The purpose of an antenna tuner is to electronically lengthen or shorten
the physical antenna so as to better match the wavelength of a
particular broadcast frequency. Whole waves, half waves quarter waves
are better than some random wavelength chopping when it comes to
propagation and reception on the other end.
Operating without the tuner will not harm your transmitter. It will only
degrade its transmit efficiency somewhat.
Cross-posted to AFPF in the hopes that one Lloyd Bonafide who is a radio
expert might comment and affirm my thoughts.
Wilbur Hubbard
For maximum power transmitted from the radio the antenna impedance has to
be the complex conjugate of the output impedance of the radio
transmitter. So the antenna and radio must have the same resistive (real)
impedance and their reactive (imaginary) impedances must sum to zero. If
the impedances are not matched, the voltage waves from the transmitter
will reflect from the antenna input and travel back to the transmitter.
The could result in heating of the output amplifier and eventually lead
to its destruction. The antenna length determines its input impedance and
radiation pattern. The tuner, at its simplest, is an electronic network,
usually pi configured, and works to transform the real part of the two
impedances to be equal at a given frequency and the reactive parts to be
zero. Multiple pi stages allow greater tuning ranges.
Bottom line, you can probably get away with short transmissions (like in
aircraft) and intermittently heat up your output stage. If your life
depends on it, get a tuner. You can use an SWR bridge to measure the
degree of mistune:
http://www.packetradio.com/catalog/i...oducts_id=2174
The amateur radio gear will work for marine radio, for $40 it's a handy
thing to have, considering a shop will charge you more for the service.
You can receive without damage with no tuner.
You may damage the radio by transmitting without a tuner.
I just looked up that ICOM-735. It's an amateur radio rig, I thought you
were asking about marine radio. Do you have a license to operate it? If
you did you wouldn't be asking that type of question and you would know
how to get around the heating up the output stage. If you don't have a
general class or better license, don't operate that radio - it's illegal.
Keep the stooges on the internet and off of the airwaves.
Poor Hanz (OP) does sound pretty clueless. And, as massively intelligent
as I am I can't really understand, intuitively, a lot of what you wrote
but I believe it as your, sir, are the expert par excellence. I couldn't
help noticing how soundly you humiliated one BobG in such a discussion and
many others.
The topic sure is more complicated than I thought, but, then again I would
not have an amateur radio transmitter aboard. Just so much power-hogging
clutter to detract from the real reason to be out there cruising. Besides,
what's wrong with a sat phone? Why operate in the dark ages of amateur
radio semi-reliability?
Wilbur Hubbard
My brilliance is only exceeded by yours, which is quite exceptional. I must
agree, in the larger picture, that a squealing, static ridden radio detracts
from the very purpose of blue water cruising. A radio like that is almost as
bad as having a woman on board - the endless chatter, complaining, pheromone
discharges and the like. One would be better off with 10 years hard labor at
a tropical penal colony. In addition, the large antenna required for such an
outdated device only serves to attract lightning. A satellite phone is a
simple, compact way to communicate with others should the need arise. It is
also portable on land whereas a marine SSB is not. I hope that you continue
your public service in enlightening others to the traditions and virtues of
true manliness and keep the bar high so liberals cannot ruin such things.
They have destroyed fly fishing ( a sport once exclusive to well bred
Republicans), seal clubbing, demolition derbies and have their sights upon
such things as blue water cruising and pirate sport hunting in coastal
Somolia. May the good fortune of a high capacity magazine be with you
Wilbur, God bless you, the USMC, the US Constitution and those who support
it in its original intent.