Long wire to SO-239 50 ohm?
 

On Wed, 24 Jan 2007 09:12:43 -0500, Meat Plow
wrote:


Anything special needed to make this thing besides the wire and SO-239?

I might want to transmit through this some day using a random wire tuner
but for now it will be used for SWL.

Go ahead and hook it directly to a random wire tuner, and simply tune
for maximum loudness on a given frequency. MFJ makes an inexpensive
tuner for random wires.

bob
k5qwg

Long wire to SO-239 50 ohm?
 

On Wed, 24 Jan 2007 14:52:51 -0500, Meat Plow
wrote:

On Wed, 24 Jan 2007 12:32:51 -0600, Bob Miller Has Frothed:

On Wed, 24 Jan 2007 09:12:43 -0500, Meat Plow
wrote:


Anything special needed to make this thing besides the wire and SO-239?

I might want to transmit through this some day using a random wire tuner
but for now it will be used for SWL.

Go ahead and hook it directly to a random wire tuner, and simply tune
for maximum loudness on a given frequency. MFJ makes an inexpensive
tuner for random wires.

bob
k5qwg

Thanks, would rather get a 10:1 balun for now. Haven't had the time to
google it but there should be some instructions on how to make one myself.


If you use a cable TV Balun you'll get a quick and dirty 4:1
transformer and a marked improvement.

http://www.radioshack.com/product/in...tPage= search

Long wire to SO-239 50 ohm?
 

In article ,
David wrote:

On Wed, 24 Jan 2007 14:52:51 -0500, Meat Plow
wrote:

On Wed, 24 Jan 2007 12:32:51 -0600, Bob Miller Has Frothed:

On Wed, 24 Jan 2007 09:12:43 -0500, Meat Plow
wrote:


Anything special needed to make this thing besides the wire and SO-239?

I might want to transmit through this some day using a random wire tuner
but for now it will be used for SWL.

Go ahead and hook it directly to a random wire tuner, and simply tune
for maximum loudness on a given frequency. MFJ makes an inexpensive
tuner for random wires.

bob
k5qwg

Thanks, would rather get a 10:1 balun for now. Haven't had the time to
google it but there should be some instructions on how to make one myself.


If you use a cable TV Balun you'll get a quick and dirty 4:1
transformer and a marked improvement.

http://www.radioshack.com/product/index.jsp?productId=2103912&cp=&sr=1&origkw=matchi ng+transformer&kw=matching+transformer&parentPage= search

Those don't work well below 10 MHz. 15 MHz and higher they are OK.

--
Telamon
Ventura, California

Long wire to SO-239 50 ohm?
 

On Thu, 25 Jan 2007 03:06:28 GMT, Telamon
wrote:


If you use a cable TV Balun you'll get a quick and dirty 4:1
transformer and a marked improvement.

http://www.radioshack.com/product/index.jsp?productId=2103912&cp=&sr=1&origkw=matchi ng+transformer&kw=matching+transformer&parentPage= search

Those don't work well below 10 MHz. 15 MHz and higher they are OK.

How do you know?

What is the low frequency limiting component?

Long wire to SO-239 50 ohm?
 

In article ,
David wrote:

On Thu, 25 Jan 2007 03:06:28 GMT, Telamon
wrote:


If you use a cable TV Balun you'll get a quick and dirty 4:1
transformer and a marked improvement.

http://www.radioshack.com/product/in...2&cp=&sr=1&ori
gkw=matching+transformer&kw=matching+transformer&p arentPage=search

Those don't work well below 10 MHz. 15 MHz and higher they are OK.

How do you know?

I tested them.

What is the low frequency limiting component?

I didn't go as far as that. This unit is made of a ferrite core and a
couple of very small value capacitors. I would guess the core was the
problem.

--
Telamon
Ventura, California

Long wire to SO-239 50 ohm?
 

David - Yes : Simple + Pratical + Economical ~ RHF

Long wire to SO-239 50 ohm?
 

On Fri, 26 Jan 2007 02:03:04 GMT, Telamon
wrote:

In article ,
David wrote:

On Thu, 25 Jan 2007 03:06:28 GMT, Telamon
wrote:


If you use a cable TV Balun you'll get a quick and dirty 4:1
transformer and a marked improvement.

http://www.radioshack.com/product/in...2&cp=&sr=1&ori
gkw=matching+transformer&kw=matching+transformer&p arentPage=search

Those don't work well below 10 MHz. 15 MHz and higher they are OK.

How do you know?

I tested them.

What is the low frequency limiting component?

I didn't go as far as that. This unit is made of a ferrite core and a
couple of very small value capacitors. I would guess the core was the
problem.

I've reverse engineered a bunch of them. The ones with caps are very
rare.

Long wire to SO-239 50 ohm?
 

On Jan 26, 6:11 am, David wrote:
On Fri, 26 Jan 2007 02:03:04 GMT, Telamon





wrote:
In article ,
David wrote:

On Thu, 25 Jan 2007 03:06:28 GMT, Telamon
wrote:

If you use a cable TV Balun you'll get a quick and dirty 4:1
transformer and a marked improvement.

http://www.radioshack.com/product/in...103912&cp=&sr=...
gkw=matching+transformer&kw=matching+transformer&p arentPage=search

Those don't work well below 10 MHz. 15 MHz and higher they are OK.

How do you know?

I tested them.

What is the low frequency limiting component?

- - I didn't go as far as that.
- - This unit is made of a ferrite core and
- - a couple of very small value capacitors.
- - I would guess the core was the problem.
-
- I've reverse engineered a bunch of them.
- The ones with caps are very rare.

Offhand - I can only come up with two reasons to
put Capacitors in-side a Matching Transformer :
1 - To make it [Narrow] Band Specific {Tuned}
2 - To make it [Wide] Band Rejection {High -or- Low}

I would suspect that any TV type Matching Transformer
that had Capacitors in-side it would be designed to have
them act as part of a Low Band Rejection Filter for the
AM/MW {Shortwave} Band and 'pass' only the Higher
VHF and UHF TV Bands.

somebody educate me please ~ RHF

Long wire to SO-239 50 ohm?
 

Meat Plow wrote:
On Wed, 24 Jan 2007 12:32:51 -0600, Bob Miller Has Frothed:

On Wed, 24 Jan 2007 09:12:43 -0500, Meat Plow
wrote:

Anything special needed to make this thing besides the wire and SO-239?

I might want to transmit through this some day using a random wire tuner
but for now it will be used for SWL.
Go ahead and hook it directly to a random wire tuner, and simply tune
for maximum loudness on a given frequency. MFJ makes an inexpensive
tuner for random wires.

bob
k5qwg

Thanks, would rather get a 10:1 balun for now. Haven't had the time to
google it but there should be some instructions on how to make one myself.

Google "sw balun" and something like Sherwood Engineering. They build
nice stuff and little $$ delivered, about $12.00 I believe, their design
seemed to work better than the one's I made from various diagrams on the
web...........

Long wire to SO-239 50 ohm?
 

In article ,
David wrote:

On Fri, 26 Jan 2007 02:03:04 GMT, Telamon
wrote:

In article ,
David wrote:

On Thu, 25 Jan 2007 03:06:28 GMT, Telamon
wrote:


If you use a cable TV Balun you'll get a quick and dirty 4:1
transformer and a marked improvement.

http://www.radioshack.com/product/in...3912&cp=&sr=1&
ori
gkw=matching+transformer&kw=matching+transformer&p arentPage=search

Those don't work well below 10 MHz. 15 MHz and higher they are OK.

How do you know?

I tested them.

What is the low frequency limiting component?

I didn't go as far as that. This unit is made of a ferrite core and a
couple of very small value capacitors. I would guess the core was the
problem.

I've reverse engineered a bunch of them. The ones with caps are very
rare.

The one you referenced has the capacitors. I would go with another model.

--
Telamon
Ventura, California