With my new K2 i have a strange AGC behavior. I cannot detect a difference
between AGC on and off. The voltage at pin 5 U2 is exactly 3.8v after changing
the 8V regulator to a better one. All my earlier k2's had a large increase in
AF when switching off AGC. I possibly made a short between pin
Hello all,
While operating my K2 and switching between bands a lot i noticed my AGC is
a bit strange.
When trying to set the AGC treshold following Don FPR's instructions i find
that the noise level is not changing with the AGC treshold pot with both
preamp on and off. There is a difference in no
Sjoerd,
When measuring millivolts some voltmeters are not very accurate. I've seen
them err as much as 40-50 percent. Compare two or three meters and see the
results. Also, some crystals don't put out a pure sine wave making RMS
measurements less acccurate. Look at it on an o'scope if one
Hi,
My K2 has been working well and I recently noticed that the AGC fast/slow has
little or no effect. I suspect it's been this way for quite some time. I made
some measurements and when performing the AGC tests on U2 (LM833), I get very
close to the expected values for the specified conditio
Someone, Don I think, posted a message this week suggesting that the
background noise with no antenna connected should be the same with AGC
either on or off. I checked mine out of curiosity and discovered that
mine was quieter with AGC on.
Before making adjustments to R1, I thought I'd run throug
Michael,
Is this new K2 as sensitive (ability to receive weak signals) as the
prior ones? If not, you have have a fault somewhere in the receiver
section.
Do strong signals activate the S-meter bargraph? Try adjusting the
S-meter (CAL S-LO and CAL S-HI) as indicated in the manual, then if you
sured Valc at some point and can tell me if these
values are way off?
Thanks again,
Sjoerd
PE2SVN
-Oorspronkelijk bericht-
Van: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] Namens Sjoerd
Verzonden: dinsdag 29 augustus 2006 22:56
Aan: elecraft@mailman.qth.net
Onderwerp: [Elecraft] K2 AGC pr
Sjoerd,
If you look at the MC1350 data sheet, you will find the AGC characteristics
for operation wiht a 12 volt supply to the chip and that graph indicates
that the gain changes almost linearly from 0 dB to 20dB with an AGC voltage
change from 5 to 6 volts, or 10 dB for a 500 mV change, and the r
Aan: Sjoerd; elecraft@mailman.qth.net
Onderwerp: RE: [Elecraft] K2 AGC problem
Sjoerd,
If you look at the MC1350 data sheet, you will find the AGC characteristics
for operation wiht a 12 volt supply to the chip and that graph indicates
that the gain changes almost linearly from 0 dB to 20dB with an
; difference in audio levels worries me..
>
> Thanks again,
>
>
> Sjoerd
> PE2SVN
>
>
> -Oorspronkelijk bericht-
> Van: Don Wilhelm [mailto:[EMAIL PROTECTED]
> Verzonden: woensdag 30 augustus 2006 14:02
> Aan: Sjoerd; elecraft@mailman.qth.net
> Onderwerp: RE: [Elec
Sjoerd,
Your AGC symptoms sound similar to some of what I found wrong with s/n 3641
when I bought it used. You can find a lot of details in the elecraft
archive - (search for "low audio on K2 s/n 3641").
Among other problems, I had a leaky C10 cap in the AGC circuit, upsetting
the AGC control ci
Jim, AB0UK wrote:
When measuring millivolts some voltmeters are not very accurate. I've seen
them err as much as 40-50 percent. Compare two or three meters and see the
results. Also, some crystals don't put out a pure sine wave making RMS
measurements less acccurate. Look at it on an o'scop
Hi,
The problem is solved. After thinking about it for a while, and not having the
PIC's data sheet, I wondered if the AGC signal was an open collector / drain
type. It turns out that pin 1 of the resistor network had never been soldered
in by the builder...not me (the builder knows who he is)
Matt,
At this point, I don't think anything is wrong with your AGC circuit.
Re-check the TEST 3 readings with the RF Gain set to MAX and I believe you
will see readings a bit closer to the Expected values (I think a step is
missing here to tell you to set the RF Gain to max). The 'key' is that t
Hi all,
i would lik evening I reconized a AGC problem on 40m band. My signal
meter shows
S8 to S9 and it sounds like RF-Gain is turned counter clockwise. If
i use ATT to reduce the signal level it does not help. The
signals will drop down but it still sounds like AGC is
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