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Old April 6th 05, 04:17 AM
starman
 
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Hi Pete,

If you have to choose only one antenna impedance input, the high one
would probably be more useful, particularly for users of real long wires
like beverage antennas. However those like myself with an inverted-L
which uses a matching transformer and coax lead would appreciate the
50-ohm input.
Is there a reason why you are considering only a BNC connector for the
low impedance input? How about a PC board mounted female F-connector
which can be adapted by the users to their antenna lead wire.

Any idea on when the MW receiver may hit the market?

Pete KE9OA wrote:

I am finishing up the MW receiver..............anyway, I have a high
impedance antenna input in addition to the 50 ohm input. With this type of
receiver is the high impedance input enough, or would interested parties
rather have both inputs.
The reason I am asking this is because my employer would like to have all
jacks mounted to the main PC board. The only thing I have been able to find
so far has been a right angle BNC connector for the 50 ohm input.
Opinions welcomed!

Pete


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Old April 6th 05, 07:00 AM
Michael A. Terrell
 
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starman wrote:

Hi Pete,

If you have to choose only one antenna impedance input, the high one
would probably be more useful, particularly for users of real long wires
like beverage antennas. However those like myself with an inverted-L
which uses a matching transformer and coax lead would appreciate the
50-ohm input.
Is there a reason why you are considering only a BNC connector for the
low impedance input? How about a PC board mounted female F-connector
which can be adapted by the users to their antenna lead wire.



The "F" connectors are 75 ohm impedance.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida
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Old April 6th 05, 12:57 PM
Pete KE9OA
 
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I have decided to include the SO-239 connector.

Pete

"Michael A. Terrell" wrote in message
...
starman wrote:

Hi Pete,

If you have to choose only one antenna impedance input, the high one
would probably be more useful, particularly for users of real long wires
like beverage antennas. However those like myself with an inverted-L
which uses a matching transformer and coax lead would appreciate the
50-ohm input.
Is there a reason why you are considering only a BNC connector for the
low impedance input? How about a PC board mounted female F-connector
which can be adapted by the users to their antenna lead wire.



The "F" connectors are 75 ohm impedance.

--
Former professional electron wrangler.

Michael A. Terrell
Central Florida



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Old April 7th 05, 03:31 AM
starman
 
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"Michael A. Terrell" wrote:

starman wrote:

Hi Pete,

If you have to choose only one antenna impedance input, the high one
would probably be more useful, particularly for users of real long wires
like beverage antennas. However those like myself with an inverted-L
which uses a matching transformer and coax lead would appreciate the
50-ohm input.
Is there a reason why you are considering only a BNC connector for the
low impedance input? How about a PC board mounted female F-connector
which can be adapted by the users to their antenna lead wire.


The "F" connectors are 75 ohm impedance.


Technically true for VHF and UHF but not that important for MW or HF
reception. I use R6U coax (75-ohm) for my HF antenna lead.

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Old April 7th 05, 03:53 AM
Michael A. Terrell
 
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starman wrote:

"Michael A. Terrell" wrote:

The "F" connectors are 75 ohm impedance.


Technically true for VHF and UHF but not that important for MW or HF
reception. I use R6U coax (75-ohm) for my HF antenna lead.


Having worked in TV broadcast and with critical telemetry video, it
does matter in a lot of applications at these frequencies. Use what you
want, but I prefer to use the proper connectors for the application, and
"F" connectors are not known for high reliability. When I ran the
repair facility for United Video one of my jobs was to test sample
connectors. A high percentage of "F" connectors didn't pass the basic
tests. They were flimsy, had bad swages between the parts and poor
plating. LIke some beautiful samples we got. They passed every test
except plating. They were un-plated brass that corroded just from body
oils.
--
Former professional electron wrangler.

Michael A. Terrell
Central Florida


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Old April 7th 05, 03:50 AM
Tom Holden
 
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"starman" wrote in message
...
"Michael A. Terrell" wrote:
The "F" connectors are 75 ohm impedance.


Technically true for VHF and UHF but not that important for MW or HF
reception. I use R6U coax (75-ohm) for my HF antenna lead.


I agree - the supposed impedance mismatch is a non-issue at these
frequencies, connectorised CATV cable is available everywhere and cheap. The
SO-239 is overkill and you want to make sure it is solidly mounted because
it can be easily over-torqued. I wish they had used an F connector on the
DX-394 because the SO-239 on one of mine rotated and fractured the solder
pad on the pcb.

Tom


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Old April 7th 05, 02:29 PM
Pete KE9OA
 
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This won't be a problem with my unit.....................I will use a panel
mount component, with either a two-bolt or a four-bolt mounting pattern.

Pete

"Tom Holden" wrote in message
.. .
"starman" wrote in message
...
"Michael A. Terrell" wrote:
The "F" connectors are 75 ohm impedance.


Technically true for VHF and UHF but not that important for MW or HF
reception. I use R6U coax (75-ohm) for my HF antenna lead.


I agree - the supposed impedance mismatch is a non-issue at these
frequencies, connectorised CATV cable is available everywhere and cheap.
The SO-239 is overkill and you want to make sure it is solidly mounted
because it can be easily over-torqued. I wish they had used an F connector
on the DX-394 because the SO-239 on one of mine rotated and fractured the
solder pad on the pcb.

Tom



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Old April 7th 05, 04:08 AM
Dale Parfitt
 
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"starman" wrote in message
...
"Michael A. Terrell" wrote:

starman wrote:

Hi Pete,

If you have to choose only one antenna impedance input, the high one
would probably be more useful, particularly for users of real long

wires
like beverage antennas. However those like myself with an inverted-L
which uses a matching transformer and coax lead would appreciate the
50-ohm input.
Is there a reason why you are considering only a BNC connector for the
low impedance input? How about a PC board mounted female F-connector
which can be adapted by the users to their antenna lead wire.


The "F" connectors are 75 ohm impedance.


F connectors, like UHF connectors are non constant impedance connectors,
unlike BNC, TNC, N or SMA.

Dale W4OP


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Old April 6th 05, 12:56 PM
Pete KE9OA
 
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The receiver will definitely have a high impedance input, and for the 50 ohm
input, I will have a pad on the main PC board that the SO-239 connector
center terminal can be soldered to. I wasn't too crazy about that BNC
approach either.
Hopefully, the receiver should hit the market by the end of summer. I will
be leaving the company at the end of April, so I will get everything done
that I can. I should have an initial board layout done in the next two
weeks.

Pete

"starman" wrote in message
...
Hi Pete,

If you have to choose only one antenna impedance input, the high one
would probably be more useful, particularly for users of real long wires
like beverage antennas. However those like myself with an inverted-L
which uses a matching transformer and coax lead would appreciate the
50-ohm input.
Is there a reason why you are considering only a BNC connector for the
low impedance input? How about a PC board mounted female F-connector
which can be adapted by the users to their antenna lead wire.

Any idea on when the MW receiver may hit the market?

Pete KE9OA wrote:

I am finishing up the MW receiver..............anyway, I have a high
impedance antenna input in addition to the 50 ohm input. With this type
of
receiver is the high impedance input enough, or would interested parties
rather have both inputs.
The reason I am asking this is because my employer would like to have all
jacks mounted to the main PC board. The only thing I have been able to
find
so far has been a right angle BNC connector for the 50 ohm input.
Opinions welcomed!

Pete


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Newsgroups
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Old April 6th 05, 12:59 PM
dxAce
 
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Pete KE9OA wrote:

The receiver will definitely have a high impedance input, and for the 50 ohm
input, I will have a pad on the main PC board that the SO-239 connector
center terminal can be soldered to. I wasn't too crazy about that BNC
approach either.
Hopefully, the receiver should hit the market by the end of summer. I will
be leaving the company at the end of April, so I will get everything done
that I can. I should have an initial board layout done in the next two
weeks.


What 'brand' will the radio have on it?

dxAce
Michigan
USA



Pete

"starman" wrote in message
...
Hi Pete,

If you have to choose only one antenna impedance input, the high one
would probably be more useful, particularly for users of real long wires
like beverage antennas. However those like myself with an inverted-L
which uses a matching transformer and coax lead would appreciate the
50-ohm input.
Is there a reason why you are considering only a BNC connector for the
low impedance input? How about a PC board mounted female F-connector
which can be adapted by the users to their antenna lead wire.

Any idea on when the MW receiver may hit the market?

Pete KE9OA wrote:

I am finishing up the MW receiver..............anyway, I have a high
impedance antenna input in addition to the 50 ohm input. With this type
of
receiver is the high impedance input enough, or would interested parties
rather have both inputs.
The reason I am asking this is because my employer would like to have all
jacks mounted to the main PC board. The only thing I have been able to
find
so far has been a right angle BNC connector for the 50 ohm input.
Opinions welcomed!

Pete


----== Posted via Newsfeeds.Com - Unlimited-Uncensored-Secure Usenet
News==----
http://www.newsfeeds.com The #1 Newsgroup Service in the World! 120,000+
Newsgroups
----= East and West-Coast Server Farms - Total Privacy via Encryption
=----




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