Gidday Bob

Thanks very much for replying to my questions.
I take it then, that if you connect a screened cable between the
aerial and the receiver, the length of the cable itself does not act
as an aerial because the screening prevents this?
So if the aerial is only one "core" where do I connect the screen? I
know I could connect it at the aerial end to the car body (earth) but
what about at the receiver end? Does it have to connect at all at that
end as long as the screen is connected to the car body?
By the way, the car itself will be stationary and switched off so
hopefully I won't have the problem of interference from the car
electrics.
Also the transmitter is apparently fixed frequency 100-125MHz and the
receiver switched to this.
I'll experiment and see!
Let me know if you have any thoughts about the screen.

Thanks again

Iain (Scotland)

Bob Bob wrote in message ...
Gidday

I would suspect that the recorder unit you have is not really intended
to take a remote antenna.

Generally speaking an aerial will be a single core. The core and screen
thing you are thinking of is likely to be coaxial cable, what you could
join a aerial to a receiver with. It isnt normally suppose to pickup or
radiate signal.

Connecting the existing wing mounted aerial *might* work but you may
receive a lot of noise from car accessories/ignition etc. If your
receiver had a coaxial connector on it things would be a lot easier!

The length of the aerial is nominally a function of the operating
frequency but I doubt the unit you have would be critical in that
regard. It wont hurt to extend the aerial anyway you like. Try it!
"Real" aerials connected to transmitters tend to require tuning to work
efficiently, but since you dont know the parameters of the device you
are connecting to it there isnt much point trying to work it out..

Your biggest enemy of receiving a good signal will be if the aerial is
inside the car metalwork.. If you cant stick it out the window then at
least have it at glass level. You may find that mounting it on the sun
visor would be a good position.

Also note that mounting the transmitter and its aerial is also
important. Try and not bury it in a metalwork and if possible put it
next to a window.

Apologies for not being much help.

Cheers Bob VK2YQA (Sydney Australia)

zentace wrote:
Hello

Hope someone out there can help!
I've just started a private investigator business.
Part of the equipment I use is a recorder/receiver unit (basically a
sony tape machine with a receiver built on to it). The aerial appears
to be a black plastic coated, bendy single wire 16cm long with a small
3mm (approx) screw thread on the end which screws into the receiver.
It appears to be single core, in that, the screw thread is a solid
piece (not like a two piece jack plug for example).

I want to be able to connect an external car ariel to the receiver as
at present the receiver with the aerial screwed in is hidden inside
the car and the reception is very poor.

Some questions:
Is the aerial single core? I naively thought all aerials had a core
and screen.

Could I take a connection from the centre core of an existing wing
mounted car aerial and run a single wire to the receiver inside the
car?

If I used this method would the external car aerial have to be 16cm,
same as the plastic aerial?

Can these small 3mm screw threads on the end of the existing aerial be
bought from somewhere so I could connect my external aerial to the
receiver?

I hope this all makes sense and I would be very grateful for any
advice.

Thank you