View Single Post
  #5   Report Post  
Old March 29th 08, 10:36 AM posted to rec.radio.shortwave
RHF RHF is offline
external usenet poster
 
First recorded activity by RadioBanter: Jun 2006
Posts: 8,652
Default Shortwave Radio Listening (SWL) Longwire Antenna Balun Question ?

On Mar 28, 1:16*pm, Ian Jackson
wrote:
In message , vangellis
writesThis link shows how I have "grounded" the setup
http://www.geocities.com/qrp_baluns/LMZ-50-Ground.GIF


vangellis


It's interesting that they have one version which is described as a 10:1
impedance matching voltage transformer, for 50 ohm coax, and the other
described as a 9:1 voltage balun transformer, for 75 ohm coax. It could
be that they are essentially the same inside (why would they want to
make two different types?), but with different connectors. Neither are
actually acting as baluns (although they be using balun transformers
inside the can).

- Some time ago, there was report published of tests
- which compared the received signals levels with
- and without - this type of transformer.
- *From memory, it showed that, on most frequencies,
- there was a very noticeable increase of signal level
- into the receiver. Only on a minority of frequencies was
- there some (acceptable) reduction of level.
- I've had a quick Google, but haven't yet found this report.
- --
- Ian

IAN,

Read this Post : SWL Longwire + Low Noise Antenna
Connection + Grounding Is Key To Good Reception
Three Messages to Read -by- John Doty

http://groups.google.com/group/rec.r...bc6a2bf8acc12d

Follow the Links/URLs provided in the Message.