"Mark S. Holden" wrote in message
...
snippage

I wrote:
I went poking around the net for a while trying to
find out whether it's worth it or not, but I couldn't
find anything on the quality of the cable there. At
least any real data, that is.


Mark replied:
It's years since I bought RS cable, IIRC, the shielding
was loosely spiral wound instead of a full braid.

I dropped by and bought about 50 ft after taking a look;
it's a braid; not the tightest braid in the world, but it'll
do for the moment.

A fair number of people use RG-6 - it's 75 ohm impedance,
but the losses aren't likely to be meaningful. Home
improvement stores tend to sell quad shielded RG-6 at
a reasonable price.

The way I see it, noise is the limiting factor - so I'll gladly
trade a few db of signal strength for several db of noise
reduction.

Good point.

more snippage

I wind my own impedance matching transformers. It's easy. They
work well, and you don't need to twiddle knobs.

You need a few feet of magnet wire, and a #43 ferrite core. Here's
a link to a site with directions:

http://www.kc7nod.20m.com/new_page_1.htm

I recently bought over 100 #43 ferrites that are a little smaller
than
the one in the plans, but they work fine. If you need one, contact
me direct - I'll sell you one for a buck postpaid.

The 9:1 converter ought to work for 50 ohm cable too, with an
adjustment in number of loops, I'd imagine. Time to crack open
the books and reacquaint myself with inductance again.

Thanks for the offer; I ought to have a couple of 75-300 converters
around, so I'll see what I've got first.

--Mike L.

Michael Lawson wrote:

"Mark S. Holden" wrote in message
...
snippage

I wrote:

I went poking around the net for a while trying to
find out whether it's worth it or not, but I couldn't
find anything on the quality of the cable there. At
least any real data, that is.



Mark replied:

It's years since I bought RS cable, IIRC, the shielding
was loosely spiral wound instead of a full braid.


I dropped by and bought about 50 ft after taking a look;
it's a braid; not the tightest braid in the world, but it'll
do for the moment.


A fair number of people use RG-6 - it's 75 ohm impedance,
but the losses aren't likely to be meaningful. Home
improvement stores tend to sell quad shielded RG-6 at
a reasonable price.

The way I see it, noise is the limiting factor - so I'll gladly
trade a few db of signal strength for several db of noise
reduction.


Good point.

more snippage

I wind my own impedance matching transformers. It's easy. They
work well, and you don't need to twiddle knobs.

You need a few feet of magnet wire, and a #43 ferrite core. Here's
a link to a site with directions:

http://www.kc7nod.20m.com/new_page_1.htm

I recently bought over 100 #43 ferrites that are a little smaller

than

the one in the plans, but they work fine. If you need one, contact
me direct - I'll sell you one for a buck postpaid.


The 9:1 converter ought to work for 50 ohm cable too, with an
adjustment in number of loops, I'd imagine. Time to crack open
the books and reacquaint myself with inductance again.

Thanks for the offer; I ought to have a couple of 75-300 converters
around, so I'll see what I've got first.

--Mike L.


Good luck with it.

I bend the wire so it's next to itself for the first ten turns, so I can
wind the primary and secondary at once.

I use a hot glue gun to tack the wire down to the ferrite when I start
to wind the transformer, and as each winding ends. (3 drops total)

Until I installed my first one, I never would have believed how much of
an improvement they make.

"Mark S. Holden" wrote in message
...
Michael Lawson wrote:

"Mark S. Holden" wrote in message
...
snippage

I wrote:

I went poking around the net for a while trying to
find out whether it's worth it or not, but I couldn't
find anything on the quality of the cable there. At
least any real data, that is.



Mark replied:

It's years since I bought RS cable, IIRC, the shielding
was loosely spiral wound instead of a full braid.


I dropped by and bought about 50 ft after taking a look;
it's a braid; not the tightest braid in the world, but it'll
do for the moment.


A fair number of people use RG-6 - it's 75 ohm impedance,
but the losses aren't likely to be meaningful. Home
improvement stores tend to sell quad shielded RG-6 at
a reasonable price.

The way I see it, noise is the limiting factor - so I'll gladly
trade a few db of signal strength for several db of noise
reduction.


Good point.

more snippage

I wind my own impedance matching transformers. It's easy. They
work well, and you don't need to twiddle knobs.

You need a few feet of magnet wire, and a #43 ferrite core.
Here's
a link to a site with directions:

http://www.kc7nod.20m.com/new_page_1.htm

I recently bought over 100 #43 ferrites that are a little smaller

than

the one in the plans, but they work fine. If you need one,
contact
me direct - I'll sell you one for a buck postpaid.


The 9:1 converter ought to work for 50 ohm cable too, with an
adjustment in number of loops, I'd imagine. Time to crack open
the books and reacquaint myself with inductance again.

Thanks for the offer; I ought to have a couple of 75-300
converters
around, so I'll see what I've got first.

--Mike L.


Good luck with it.

I bend the wire so it's next to itself for the first ten turns, so I
can
wind the primary and secondary at once.

I use a hot glue gun to tack the wire down to the ferrite when I
start
to wind the transformer, and as each winding ends. (3 drops total)

Until I installed my first one, I never would have believed how much
of
an improvement they make.

Okay, after a couple of days of scrounging around and a
trip or two to visit the Rat Shack (for wire and a smaller
project box), I've got mine up and running. Listening to
it this evening and comparing Radio Sweden from last
night to this night is actually very interesting. You can
actually hear a difference in the quality; less noise and
a degree or so of less fading. The signal strength doesn't
seem to have improved much, but the noise has definitely
dropped a bit.

Last night, I actually had to use the 4.0 kHz
filter to keep Radio Havana from swamping the signal
at times, but there's nary a problem tonight. Oh, I can
still hear a bit of Radio Havana in the background, but
the rejection is better this time around. Listening to
the Voice of Greece's broadcast to Europe earlier this
evening, I usually can't pick it up intelligibly at all, but
I was able to listen without much trouble tonight due
to the drop in the noise.

Methinks I'm going to do a bit more bandscanning tonight
to see what else I can pick up that I couldn't before...

Thanks for the help, guys, but now I've got that
damned tinkering bug again, and I'll probably be
putting it to use converting the high pass SW filter
that I homebrewed years ago to something I can
use these days (like putting a switch inline with it
so I can bypass it as needed).

--Mike L.