Long wire to SO-239 50 ohm?
 

In article .com,
"RHF" wrote:

On Jan 25, 6:03 pm, 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.


Some of the better 300 Ohm to 75 Ohm TV type Matching Transformers
are labeled as being good down to 5 MHz. Usually these are the {Gold
Plated} ones designed for Cable and Satellite TV used.

? Honestly ? What good does the Gold Plating do on the "F" Connector
and the Spade Connectors : When it is the internal components that
will determine the real quality of the signal entering one end and
exiting the other.

The gold plating on the contacts is so there is no corrosion or
oxidation on the connector mating surface. If you don't have a good DC
connection you don't have a good circuit for RF either. Gold is a nobel
metal that does not oxidize.

They work 'ok' for a basic Shortwave Listener (SWL)
Random Wire Antenna "Matcher" with moderate size
{Lenght} Antennas in the range of 20-60 Feet.

Plus they have the extra advantage of attenuating those
High Power AM/MW Radio Stations below 1.8 MHz.


at least this has been my experience - speaking
of "quick and dirty" - hey that's me - iane ~ RHF

Yeah they will do that. Problem is they will not work so well on 41, 49,
60, 75, 90, and 120 either.

--
Telamon
Ventura, California

About Baluns - What is the Best Balun ?
 

On Jan 26, 9:21 am, "RHF" wrote:
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}

Example - Shortwave Baluns and Accessories
http://www.kintronic.com/site/subassemblies/baluns.asp
Kintronic Laboratories offers two types of Shortwave Baluns.
First is a discrete Discrete Component Shortwave Balun
with Tunable Capacitors to permit a 1:1 Match at any
Frequency in a Single Shortwave (HF) Band of operation.

New Longwire Balun 9:1 Transformer High Performer
-by- LowBander on eBay
http://cgi.ebay.com/_W0QQitemZ180078653482

About Baluns - What is the Best Balun ?
http://dxantennas.com/wst_page4.php

bail-um-out ~ RHF

About Baluns - What is the Best Balun ?
 

In article . com,
"RHF" wrote:

On Jan 26, 9:21 am, "RHF" wrote:
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...=2103912&cp=&s r=... 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}

Example - Shortwave Baluns and Accessories
http://www.kintronic.com/site/subassemblies/baluns.asp
Kintronic Laboratories offers two types of Shortwave Baluns.
First is a discrete Discrete Component Shortwave Balun
with Tunable Capacitors to permit a 1:1 Match at any
Frequency in a Single Shortwave (HF) Band of operation.

New Longwire Balun 9:1 Transformer High Performer
-by- LowBander on eBay
http://cgi.ebay.com/_W0QQitemZ180078653482

About Baluns - What is the Best Balun ?
http://dxantennas.com/wst_page4.php

Snip

That would depend on the application like anything engineered. In
general the current type would be best for Hertzian antennas and I would
only use the voltage type on random/long wire Marconi type antennas.

--
Telamon
Ventura, California

Long wire to SO-239 50 ohm?
 

On Fri, 26 Jan 2007 17:16:54 -0800, Telamon
wrote:

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

I was just showing the picture. If the thing has caps, replace them
with shiny jumpers.

About Baluns - What is the Best Balun ?
 

On Sat, 27 Jan 2007 12:05:57 -0800, Telamon
wrote:


Snip

That would depend on the application like anything engineered. In
general the current type would be best for Hertzian antennas and I would
only use the voltage type on random/long wire Marconi type antennas.

http://www.moonraker.com.au/techni/q...everticals.htm

About Baluns - What is the Best Balun ?
 

RHF wrote:

On Jan 26, 9:21 am, "RHF" wrote:
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}

Example - Shortwave Baluns and Accessories
http://www.kintronic.com/site/subassemblies/baluns.asp
Kintronic Laboratories offers two types of Shortwave Baluns.
First is a discrete Discrete Component Shortwave Balun
with Tunable Capacitors to permit a 1:1 Match at any
Frequency in a Single Shortwave (HF) Band of operation.

New Longwire Balun 9:1 Transformer High Performer
-by- LowBander on eBay
http://cgi.ebay.com/_W0QQitemZ180078653482

About Baluns - What is the Best Balun ?

The best ones are the ones I build myself!

I have one that has been in use since 1988.

dxAce
Michigan
USA

Long wire to SO-239 50 ohm?
 

In article ,
David wrote:

On Fri, 26 Jan 2007 17:16:54 -0800, Telamon
wrote:

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

I was just showing the picture. If the thing has caps, replace them
with shiny jumpers.

Don't let me stop you from doing this and let us know how it works out.

--
Telamon
Ventura, California

About Baluns - What is the Best Balun ?
 

In article ,
David wrote:

On Sat, 27 Jan 2007 12:05:57 -0800, Telamon
wrote:


Snip

That would depend on the application like anything engineered. In
general the current type would be best for Hertzian antennas and I would
only use the voltage type on random/long wire Marconi type antennas.

http://www.moonraker.com.au/techni/q...everticals.htm

What does this have to do with BALUNs?

--
Telamon
Ventura, California

Long wire to SO-239 50 ohm?
 

On Sat, 27 Jan 2007 17:44:54 -0800, Telamon
wrote:

In article ,
David wrote:

On Fri, 26 Jan 2007 17:16:54 -0800, Telamon
wrote:

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

I was just showing the picture. If the thing has caps, replace them
with shiny jumpers.

Don't let me stop you from doing this and let us know how it works out.

It's a quick and dirty junk drawer compromise that's better than
nothing. I prefer the Palomar MLB because they're homies.

About Baluns - What is the Best Balun ?
 

On Sat, 27 Jan 2007 17:55:17 -0800, Telamon
wrote:

In article ,
David wrote:

On Sat, 27 Jan 2007 12:05:57 -0800, Telamon
wrote:


Snip

That would depend on the application like anything engineered. In
general the current type would be best for Hertzian antennas and I would
only use the voltage type on random/long wire Marconi type antennas.

http://www.moonraker.com.au/techni/q...everticals.htm

What does this have to do with BALUNs?

A random wire is not a Marconi antenna. A Marconi antenna is a 1/4
wave vertical with a formal ground screen/radial system providing a
second 1/4 wave image below the earth which allows the system to load
like (but radiate like) a half-wave antenna. A Marconi antenna is ca.
36 Ohms and needs no 9:1 or 10:1 transformer.