wrote:
I have a reciever that has 2 screw antenna connections, 300 ohm. I
currently use RG-6 coax so I use a 4:1 matching tranformer at my
reciever and also at the Windom antenna in the attic.

I would like to setup a 90 ft random wire antenna outside using the
RG-6 and feed thru a ground block to the matching transformer into my
reciever. I'll need a 9:1 balun at the feed, but have not found a
ready made balun that accepts the "F" type coax connector. The ICE-180
and one currrently on eBay use a SO-239 connector and I have not found
connectors available to adapt to the RG-6.

Does any one know of a 9:1 Balun that accepts the "f" type connector?

Brian

300 ohms for an HF radio?

For many reasons I doubt that.

Common balanced impedances are 150, ~450 and I have seen a few 600 Ohm
RF devices.

300 would be extreme to the limits.

What type receiver is this?

Terry

300 ohms for an HF radio?

For many reasons I doubt that.

Common balanced impedances are 150, ~450 and I have seen a few 600 Ohm
RF devices.

300 would be extreme to the limits.

What type receiver is this?

Terry

It is a Realistic DX-160. I had this model as a kid and saw the DX-160
on eBay near by and bought it.

Brian

wrote:


300 ohms for an HF radio?

For many reasons I doubt that.

Common balanced impedances are 150, ~450 and I have seen a few 600 Ohm
RF devices.

300 would be extreme to the limits.

What type receiver is this?

Terry

It is a Realistic DX-160. I had this model as a kid and saw the DX-160
on eBay near by and bought it.

The stuff I've seen on it indicates a 50 Ohm input impedence.

dxAce
Michigan
USA

dxAce wrote:
wrote:


300 ohms for an HF radio?

For many reasons I doubt that.

Common balanced impedances are 150, ~450 and I have seen a few 600 Ohm
RF devices.

300 would be extreme to the limits.

What type receiver is this?

Terry

It is a Realistic DX-160. I had this model as a kid and saw the DX-160
on eBay near by and bought it.



The stuff I've seen on it indicates a 50 Ohm input impedence.

dxAce
Michigan
USA

For the fun of it I will remove my 4:1 matching transformer between the
coax and the reciver connections and connect the coax right to the
screw terminals and see what happens.

Thanks
Brian

wrote:
dxAce wrote:
wrote:


300 ohms for an HF radio?

For many reasons I doubt that.

Common balanced impedances are 150, ~450 and I have seen a few 600 Ohm
RF devices.

300 would be extreme to the limits.

What type receiver is this?

Terry

It is a Realistic DX-160. I had this model as a kid and saw the DX-160
on eBay near by and bought it.



The stuff I've seen on it indicates a 50 Ohm input impedence.

dxAce
Michigan
USA

For the fun of it I will remove my 4:1 matching transformer between the
coax and the reciver connections and connect the coax right to the
screw terminals and see what happens.

Thanks
Brian

That's weird I didn't notice any difference in radio reception at all
between the straight coax feed or thru the 4:1 matching transformer.

Brian

wrote:
That's weird I didn't notice any difference in radio reception at all
between the straight coax feed or thru the 4:1 matching transformer.

I've read more and I'm really confused. A 90 foot random wire is unbalanced.
A DX-160 with a coax input is unbalanced. What's the balun for?

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 Fax ONLY: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

Geoffrey S. Mendelson wrote:
wrote:
That's weird I didn't notice any difference in radio reception at all
between the straight coax feed or thru the 4:1 matching transformer.

I've read more and I'm really confused. A 90 foot random wire is unbalanced.
A DX-160 with a coax input is unbalanced. What's the balun for?

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM
IL Voice: (07)-7424-1667 Fax ONLY: 972-2-648-1443 U.S. Voice: 1-215-821-1838
Visit my 'blog at http://geoffstechno.livejournal.com/

I'm getting more confused the more I read replies and on the net and
I'm starting to wonder also.

But my reasoning is... I thought the input impedance of the reciever
at the terminals was 300 ohms. I am using a 4:1 matching transformer
at the antenna (currently a 70ft windom) to feed into 75 ohm RG-6 coax.
The 4:1 matching transformer at the reciever was to return the input
to 300 ohms.

I'm going to do some more reading up on this.

Brian

dxAce wrote:
wrote:


300 ohms for an HF radio?

For many reasons I doubt that.

Common balanced impedances are 150, ~450 and I have seen a few 600 Ohm
RF devices.

300 would be extreme to the limits.

What type receiver is this?

Terry

It is a Realistic DX-160. I had this model as a kid and saw the DX-160
on eBay near by and bought it.

The stuff I've seen on it indicates a 50 Ohm input impedence.

dxAce
Michigan
USA

Thanks dxAce

I did some digging and the DX-160 definitely has a low impedance
antenna input.
I was under the impression that it was 300 ohm.
I removed the 4:1 matching transformer that I installed at the reciever
which would bring the input back to about 75 ohms and saw no difference
in the signal so it may not be that important anyways in a recieve only
setup.

Not that I doubted you.

Brian