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

"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

Pete - One of these two :

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

Thanks! SE is an engineering firm that is primarily involved in the
automotive industry. Their biggest project has been work on the Automark
election machine.
I convinced them to market the MW receiver............up until that point,
they didn't have an RF designer. I am not sure if they are going to get the
active loopstick antenna done before I leave............they want to
concentrate on the receiver itself.
I do have a prototype of the antenna completed...............yesterday, I
wound an antenna that has dual feedback windings for the regen circuit. The
trick now is to get smooth control of the feedback. I tried a crude form of
control using a pot for the feedback control that feeds a resistive splitter
for the coils themselves. I am thinking about a single-ended input to
differential output unity gain JFET buffer. I just need to come up with the
design, but it shouldn't be to hard.
For the control element itself, I can use the pot just to bias a JFET as the
control element..........maximum voltage at the gate runs the JFET into the
pinchoff region, which essentially turns it off..........at least,
hopefully!

Pete

"dxAce" wrote in message
...


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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Thanks!

Pete

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

It could be....................................I haven't checked on that
one!

Pete

"Greg" wrote in message
...


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

That is the place! Feel free to call me if you have any
questions.............maybe it will get the ball rolling faster!

Pete

"RHF" wrote in message
ups.com...


Pete - One of these two :
.
Silicon Engines Ltd
2101 Oxford Road
Des Plaines, IL (Illinois) 60018-1919
Phone: (847) 803-6860
http://www.siliconengines-ltd.com/
.
Quadphase Corporation
2101 Oxford Road
Des Plaines, IL (Illinois) 60018-1919
Phone: (847) 803-4077
.
~ RHF
. . . . .