Brian Gregory [UK] wrote:
wrote in message
...
Because the presently made MLB-1 by Palomar Engineersis a UNUN for a
longwire. The older transformer which I used (may have the original
instruction paper somewhere) was a true BALUN. To build a T2FD we must
use a balun, since it is a broadband dipole.

A long wire balun should not assume you want a common ground connection on
the input and output.

But I've look at the picture and description of the MLB-1 on the web and I
agree it's far from clear what connections are provided.

However if I bought it and found it did have the grounds joined I'd return
it as unacceptable because when using a long wire you want to use a separate
good quality earth which is not joined to your receiver's earth which may
have RF noise on it.


I disagree. Use on an UnUn (autotransformer) puts all points of the
system at ground, provided you ground per electrical code. "Noise" from
the radio chassis (?) flows to ground through the IEC cable. Static
charges from the antenna system flow to ground at the transmission line
point of entry.

On Sep 3, 9:15*pm, dave wrote:
Brian Gregory [UK] wrote:
*wrote in message
...
Because the presently made MLB-1 by Palomar Engineersis a UNUN for a
longwire. The older transformer which I used (may have the original
instruction paper somewhere) was a true BALUN. To build a T2FD we must
use a balun, since it is a broadband dipole.

A long wire balun should not assume you want a common ground connection on
the input and output.

But I've look at the picture and description of the MLB-1 on the web and I
agree it's far from clear what connections are provided.

However if I bought it and found it did have the grounds joined I'd return
it as unacceptable because when using a long wire you want to use a separate
good quality earth which is not joined to your receiver's earth which may
have RF noise on it.

I disagree. Use on an UnUn (autotransformer) puts all points of the
system at ground, provided you ground per electrical code. *"Noise" from
the radio chassis (?) flows to ground through the IEC cable. Static
charges from the antenna system flow to ground at the transmission line
point of entry.- Hide quoted text -

- Show quoted text -

My own cell-phone generates more noise than some of the cold war era
jammers,sometimes! That is another reason for using coax. And
grounding may bring more problems,sometimes it is better not to
ground. Static usually is not a major issue over here at my lattitude
(40* N).

wrote:

- Show quoted text -

My own cell-phone generates more noise than some of the cold war era
jammers,sometimes! That is another reason for using coax. And
grounding may bring more problems,sometimes it is better not to
ground. Static usually is not a major issue over here at my lattitude
(40* N).

GMS phones seem to get into everything. I'd look for an audio path, not
via HF radio circuitry.

Snow blowing across a wire antenna generates static electricity.
Grounding the transmission line where it enters a structure is
consistent with good operating practice. My radio floats on a 13 VDC
switch mode power supply. The only ground is the coaxial cable from the
feedthru.

dave wrote:
wrote:

- Show quoted text -

My own cell-phone generates more noise than some of the cold war era
jammers,sometimes! That is another reason for using coax. And
grounding may bring more problems,sometimes it is better not to
ground. Static usually is not a major issue over here at my lattitude
(40* N).

GMS phones seem to get into everything. I'd look for an audio path, not
via HF radio circuitry.

Snow blowing across a wire antenna generates static electricity.
Grounding the transmission line where it enters a structure is
consistent with good operating practice. My radio floats on a 13 VDC
switch mode power supply. The only ground is the coaxial cable from the
feedthru.


GSM?

"dave" wrote in message
. ..
wrote:

- Show quoted text -

My own cell-phone generates more noise than some of the cold war era
jammers,sometimes! That is another reason for using coax. And
grounding may bring more problems,sometimes it is better not to
ground. Static usually is not a major issue over here at my lattitude
(40* N).

GMS phones seem to get into everything. I'd look for an audio path, not
via HF radio circuitry.

Snow blowing across a wire antenna generates static electricity. Grounding
the transmission line where it enters a structure is consistent with good
operating practice. My radio floats on a 13 VDC switch mode power supply.
The only ground is the coaxial cable from the feedthru.

Have you tried using batteries, or even a linear power supply.
You may be amazed how much noise on the lower bands just vanishes when you
do.

--

Brian Gregory. (In the UK)

To email me remove the letter vee.

"dave" wrote in message
. ..
Brian Gregory [UK] wrote:
wrote in message
...
Because the presently made MLB-1 by Palomar Engineersis a UNUN for a
longwire. The older transformer which I used (may have the original
instruction paper somewhere) was a true BALUN. To build a T2FD we must
use a balun, since it is a broadband dipole.

A long wire balun should not assume you want a common ground connection
on
the input and output.

But I've look at the picture and description of the MLB-1 on the web and
I
agree it's far from clear what connections are provided.

However if I bought it and found it did have the grounds joined I'd
return
it as unacceptable because when using a long wire you want to use a
separate
good quality earth which is not joined to your receiver's earth which may
have RF noise on it.


I disagree. Use on an UnUn (autotransformer) puts all points of the system
at ground, provided you ground per electrical code. "Noise" from the
radio chassis (?) flows to ground through the IEC cable. Static charges
from the antenna system flow to ground at the transmission line point of
entry.

All I ccan suggest is that you try it.

If I comapre reception on the lower bands between using my own earth made
from a copper pipe hammered into the ground somewhat away from the house to
that using the mains earth I find there is way more noise using the mains
earth and using both earths is almost as bad.

--

Brian Gregory. (In the UK)

To email me remove the letter vee.