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Pete KE9OA April 6th 05 12:57 PM

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




dxAce April 6th 05 12:59 PM



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


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Pete KE9OA April 6th 05 01:00 PM

Hi Eric,
I have decided to use an SO-239 for the low impedance input. For
the high impedance input, I will be using a Mini-Circuits 4:1 transformer.
The good thing about this approach is that the high impedance can come in at
the transformer input while the low impedance can come in between either one
of the balanced inputs and ground, the same way it is done in FM tuners.
This way, the low-pass image reject filter doesn't get perturbed. This also
eliminate the necessity of having an external matching device (believe me, I
considered this avenue!).

Pete

"Eric F. Richards" wrote in message
...
"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,

I'm in favor of the low-Z input myself. I wouldn't want to connect a
"wire" to any receiver without some robust -- and sacrificial --
isolation.

Would your boss be in favor of using (or recommending one of the
existing) an external impedence matching device with binding posts on
it?

Pete


Eric

--
Eric F. Richards

"Nature abhors a vacuum tube." -- Myron Glass,
often attributed to J. R. Pierce, Bell Labs, c. 1940




Pete KE9OA April 6th 05 01:01 PM

I think you are correct Terry.............take a look at my prior responses.
This will illustrate the approach I have chosen. It should work out well.

Pete

wrote in message
ups.com...

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


Add a switch to change the BNC from low-Z to high-Z.
Include a BNC to dual banana adaptor.
The slight notch in impedence shouldn't matter.
And I would bet that any effect on reception could NOT be measured.

Terry




Pete KE9OA April 6th 05 01:16 PM

I am thinking that it will be either Silicon Engines or most likely,
Quadphase. This company has two divisions.

Pete

"dxAce" wrote in message
...


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

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dxAce April 6th 05 01:20 PM



Pete KE9OA wrote:

I am thinking that it will be either Silicon Engines or most likely,
Quadphase. This company has two divisions.


Well, Silicon Engines does sound pretty neat.



Pete

"dxAce" wrote in message
...


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

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120,000+
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[email protected] April 6th 05 01:47 PM

Silicon Engines? That sounds good for a name for a Radio.
cuhulin


Greg April 6th 05 11:29 PM



From: "Pete KE9OA"
Organization: AT&T Worldnet
Newsgroups: rec.radio.shortwave
Date: Wed, 06 Apr 2005 12:16:46 GMT
Subject: High performance MW receiver

I am thinking that it will be either Silicon Engines or most likely,
Quadphase. This company has two divisions.

Pete

Doesn't Pamela Anderson have silicone engines?

Sorry, the devil made me say it.

Greg


starman April 7th 05 03:31 AM

"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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Tom Holden April 7th 05 03:50 AM

"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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