On 01/17/2014 09:51 PM, Tom W8JI wrote:
Intermod is a function of the TOTAL voltage of all the signal sources at the
point where the diodes are. This is why some systems work with diodes, and
some systems completely fall apart. The problem can come from a hundred
small signals, each signal far
On 01/18/2014 06:20 AM, N1BUG wrote:
Indeed. I've had problems with ICE 196 receiver protectors for
several years. I assume the intermod is generated by the diodes in
those devices, though I do not know that for a fact. The problem
occurs on nights when propagation is very good both in the AM BC
Thanks to all for the insightful replies/advice. It would appear the use of
clamping FETs is worth a try...
72, Jim R. K9JWV
_
Topband Reflector Archives - http://www.contesting.com/_topband
Indeed. I've had problems with ICE 196 receiver protectors for several
years. I assume the intermod is generated by the diodes in those devices,
though I do not know that for a fact. The problem occurs on nights when
propagation is very good both in the AM BC band and shortwave in the 5-7
MHz
Jim,
Getting directly back to your original question, I built a KD9SV preamp,
and it has clamp diodes included in the design (I did not add them, they
were part of the original design by KD9SV). Does you KD9SV preamp already
have clamp diodes protecting its input, and if so you have already
and work y'all with my QRP peanut
whistle!
Date: Sat, 18 Jan 2014 13:53:01 -0500
Subject: Re: Topband: To clamp or NOT...that IS the question
From: wd8...@gmail.com
To: rodenkirch_...@msn.com
Hi Jim,
You might post that info to the topband reflector (about your preamp having
clamp diodes already
When I build a preamp I install the cupped machine pins from an IC socket in
the protection device mounting holes so that I can experiment with different
protective devices and easily replace devices which have been damaged.
If you have IMD from back to back diodes try two or three diodes in
Subject: Topband: To clamp or NOT...that IS the question
A friend of mine is building me a switching arrangement with a reed relay to
switch between my transmit antenna and a receive delta loop to the one
antenna input for my Ten Tec Jupiter (I operate at QRP levels for contests).
As an added
Hello Jim,
3x fast relays, 2x switching transistors, 3x resistors and box with
connectors...
You have KD9SV front-end saver. No diodes, no RX performance
degradation.
I never had issue on my K3 with KD9SV saver in ext.RX front-end.
Let me know I will send You the drawing.
Hope it helps my
Hi Jim and gang,
I use protection diodes on the front end of my W1FB preamps (as well as
before an IC amp in the preamp, and on the output of the preamp) and have
never been able to detect receiver performance degradation on 160 meters
due to the clamping diodes (had to include the diode clamps
I use protection diodes on the front end of my W1FB preamps (as well as
before an IC amp in the preamp, and on the output of the preamp) and have
never been able to detect receiver performance degradation on 160 meters
due to the clamping diodes (had to include the diode clamps before the IC
amp
Hi Tom,
You said : What works OK in one place will almost always not work the same
in another
You just confirmed what I was trying to say, and that is in some
applications it just might work. If I had not tried simple clamp diodes in
my application I would have made my system complicated via
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