High performance MW receiver
 

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

Pete [KE9OA],

In a straight line,it is only fifty miles from where I live here in the
West side of Jackson,Mississippi to Monticello,Mississippi.Will that
radio pick up that AM station in Monticello in the daytime from Jackson
without an external antenna? If not,take it back to the drawing board.
cuhulin

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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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

"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 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

The progress is very good for the Loop Antenna, meaning that I built up a
prototype this weekend. It works very well. Later on this week, I will be
doing more experimentation with a regeneration circuit. Since the loopstick
is balanced, I am thinking about adding a feedback winding at each end of
the loopstick; this way, balance is maintained. It uses the common diff-amp,
with a pair of JFETs that are buffered with an emitter follower. I am using
Varactor tuning........the advantage with this approach is
twofold.........first of all, it eliminates that hard to get tuning
capacitor, and secondly, it eliminates the proximity effect from you hand
when tuning because the tuning voltage point for the Varactor is at AC
ground.

Pete

"RHF" wrote in message
oups.com...
Pete [KE9OA],
.
Glad to hear that the work continues
and that the project is near completion.
.
What is the status of your Loop Antenna - Option ?
.
waiting and hoping ~ RHF
. . . . .

With the active loopstick, it shouldn't be a problem..........that is, if
the signal that you are looking for is above the ambient noise level.
Remember those ads for the Drake SW-4 receiver? They would always say "if
conditions permit, you will be able to hear the signal".
I think you be happy with the radio. I had a visitor from Minnesota a few
weeks ago. When he heard one of the prototypes, he said "let me know when it
hits the market". (slightly paraphrased). He was impressed with the audio
performance of the prototype, and this was just using an LM386 as the audio
amp. The final design will use an automotive power amp, with a really cool
audio processor ahead of it.

Pete

wrote in message
...
In a straight line,it is only fifty miles from where I live here in the
West side of Jackson,Mississippi to Monticello,Mississippi.Will that
radio pick up that AM station in Monticello in the daytime from Jackson
without an external antenna? If not,take it back to the drawing board.
cuhulin

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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