I received my KRX3 earlier this year (I think), but I am just now
installing it. I have a question about the TMP cable sockets on the KRX3
board. When the sheilded enclosure is installed it touches these connectors.
Is this ok, or should these connectors be isolated from the shield?
Stan,
All those shields should be grounded, so it is OK if they touch the shields.
73,
Don W3FPR
sr...@swbell.net wrote:
I received my KRX3 earlier this year (I think), but I am just now
installing it. I have a question about the TMP cable sockets on the KRX3
board. When the sheilded
I have been chasing Midway Isl (K4M) and using my sub-RX to follow the pack.
When K4M was not real loud I would turn the Sub off to get the audio in both
ears then back on. After doing that several times (perhaps 10 - 15) the
Sub-RX turns on (according to the front panel icon) but there is no
Subject: [Elecraft] K3 - KRX3 question
I have been chasing Midway Isl (K4M) and using my sub-RX to follow the
pack.
When K4M was not real loud I would turn the Sub off to get the audio in
both
ears then back on. After doing that several times (perhaps 10 - 15) the
Sub-RX turns on (according
Bruce Meier wrote:
I have been chasing Midway Isl (K4M) and using my sub-RX to follow the
pack. When K4M was not real loud I would turn the Sub off to get the
audio in both ears then back on. After doing that several times
(perhaps 10 - 15) the Sub-RX turns on (according to the front panel
Just tried it for about at least 50 times in a row, always get the
sub-receiver audio without a problem. I'm also using. 3.44.
73 de Roland, DC1RS
-
K3/100 #1243, KFL3A-2.8K, KFL3A-2.1K, KFL3A-400, KRX3, KFL3A-2.8K, KFL3A-400,
KAT3
--
View this message in context:
Same hear.
73
Stewart G3RXQ
On Sun, 18 Oct 2009 05:14:56 -0700 (PDT), DC1RS wrote:
Just tried it for about at least 50 times in a row, always get
the
sub-receiver audio without a problem. I'm also using. 3.44.
73 de Roland, DC1RS
-
K3/100 #1243, KFL3A-2.8K, KFL3A-2.1K, KFL3A-400,
Hi Bruce:
I have been using the same procedure as you on CW with the last bunch of
DXpeditions and I haven't had the exact problem you described. But I have
noticed that sometimes it takes a second for the SUB to come alive. I get a
squeaky sound in the right ear as if the SUB is squeezing out
Joe Subich, W4TV-3 wrote:
This is not the case based on careful measurements. The problem
is 'skirt sharpening' when multiple filters are cascaded. Where
a single filter might have a 6dB bandwidth of 225 Hz (200 Hz
roofing fitter), when combined with the 200 Hz DSP filter the
Ed Muns wrote:
What DSP bandwidths were you using and where did you have your crystal
filters engaging? There is only a 65 Hz bandwidth difference between the
400 and 250 crystal filters and both are wider than the what is needed
for 170 Hz shift RTTY. The crystal filter function is to
David Woolley (E.L) wrote:
Ed Muns wrote:
What DSP bandwidths were you using and where did you have your crystal
filters engaging? There is only a 65 Hz bandwidth difference between the
400 and 250 crystal filters and both are wider than the what is
needed
for 170 Hz shift RTTY. The
FYI, the DSP filter in the K3 follows the following formula for shape factor
according to Lyle KK7P:
Shape Factor = (6 dB BW) / (6 dB BW + 300 Hz)
Oops...no coffee yet. Make that
Shape Factor = (6 dB BW + 300 Hz) / (6 dB BW)
73, Bill
--
View this message in context:
Bill
I can't recall seeing that figure published before; where would I look for that
figure?
David
G3UNA
snip
The purpose of the roofing filter is mainly to reduce strong (approximately
S9+30) signals from over-driving the ADC in the DSP. If they do that, then
the DSP determines the
David Cutter wrote:
Bill
I can't recall seeing that figure published before; where would I look for
that figure?
David
G3UNA
snip
The purpose of the roofing filter is mainly to reduce strong
(approximately
S9+30) signals from over-driving the ADC in the DSP. If they do
Thanks Bill, it was the first 2 that were of interest.
David
G3UNA
David Cutter wrote:
Bill
I can't recall seeing that figure published before; where would I look for
that figure?
David
G3UNA
snip
The purpose of the roofing filter is mainly to reduce strong
2. 100 dB dynamic range of DSP. I'm not going to search for the exact
source but this is often quoted by manufacturers as the practical limit of
current DSPs using 24-bit ADCs. Theoretically it should be higher based
only on 24-bit ADC resolution but practically it's limited by other factors.
Bill,
I find the diversity option interesting and I imagine that it will be a very
useful feature on topband. In what other situations do you find it useful?
I have never tried diversity myself, what would the difference be between a
filter matched to the specs provided Elecraft and a set of
Mohr [EMAIL PROTECTED]
To: Elecraft Reflector elecraft@mailman.qth.net
Sent: Monday, July 07, 2008 9:10 AM
Subject: Re: [Elecraft] K3: KRX3 question
Bill,
I find the diversity option interesting and I imagine that it will be a
very
useful feature on topband. In what other situations do you find
Björn Mohr SM0MDG wrote:
I find the diversity option interesting and I imagine that it will be a
very
useful feature on topband. In what other situations do you find it useful?
I have never tried diversity myself, what would the difference be between
a
filter matched to the specs
Bill
I don't follow how filter offsets degrade oscillator tracking, ie to make a
beat frequency. Sorry if I'm being thick.
David
G3UNA
What would be the effect of unmatched filters? You would have a beat
frequency, such as I mentioned with Orion above, which would be the
difference in
With two synthesizers, our software must calculate the proper PLL
divider and reference frequencies for each one. When setting the sub and
main to the same RX frequency, if the filter offsets set in the menu are
different this can cause small rounding errors in the synthesizer
frequency
Thanks for the input, this is really interesting!
On 2008-07-07 19.23, Eric Swartz - WA6HHQ, Elecraft [EMAIL PROTECTED]
wrote:
With two synthesizers, our software must calculate the proper PLL
divider and reference frequencies for each one. When setting the sub and
main to the same RX
07, 2008 7:05 AM
To: elecraft@mailman.qth.net
Subject: Re: [Elecraft] K3: KRX3 question
David Woolley (E.L) wrote:
Ed Muns wrote:
What DSP bandwidths were you using and where did you have your
crystal filters engaging? There is only a 65 Hz bandwidth
difference
between
Joe Subich, W4TV-3 wrote:
Bill,
David you may be suggesting that in theory but I would pay
*close attention* to what W0YK says. Ed wins many RTTY contests
including several current world records from P49X, and results
sometimes speak louder to me than theory (and I'm an engineer
Being tha t it was mentioned that best responses seem to be with a
roofing filter wider than 300Hz and then he mentioned the 250Hz filter
wouldn't you deduce that he meant the 370Hz filter which Elecraft calls
250Hz? I mean maybe I'm jumping to conclusions here but that was pretty
clear to me.
KFL3A-250 K3 250 Hz, 8 pole filter
- Original Message -
From: Bill W4ZV [EMAIL PROTECTED]
That's interesting since there isn't a 250 Hz roofing filter. There's a
370
Hz and a 224 Hz, but no 250 Hz. What did you use for the 250 measurement
above or is that a calculated result? At
Brett Howard wrote:
Being tha t it was mentioned that best responses seem to be with a
roofing filter wider than 300Hz and then he mentioned the 250Hz filter
wouldn't you deduce that he meant the 370Hz filter which Elecraft calls
250Hz? I mean maybe I'm jumping to conclusions here but
Direct quote from the message:
Much of the narrowing is due to the very humped (Gaussian)
nature of the narrow crystal filters but the best responses
for RTTY seem to be with a roofing filter wider than 300 Hz
(the 250 Hz/8-pole) and/or keeping the DSP filter wider than
250 Hz with or
Brett Howard wrote:
So am I to assume that the 8-pole filters are not going to need to worry
about this as they are all at 0 anyway? What is the advantage of
getting two matched pairs of 5-pole filters when you can get two 8-poles
for only 10 bucks a filter more?
I'm assuming that its
Hi Bill,
If you worked RTTY you would find out that the 250Hz filter is ideal
for recovering weak ones and for 20M during RTTY contests. The dual
passband filter fits very nicely within it. I don't care what
bandwidth you call it. Don't eliminate it as a choice.
I was astounded the
I think I must be missing something.
As I understand it, the additional crystal filters are only really necessary
when operating with very strong adjacent signals in the passband. So, if
you don't have a need for rejection of such strong signals, let's say 40
over S9 (somebody correct this
David,
In most instances, you are correct. My K3 has only the stock 2.7
filter, but then I am not into heavy contesting nor intense DX chasing -
I do some contesting and work DX for fun only. When it gets to the
point where I really need narrow roofing filters, it is time for me to
go
If you worked RTTY you would find out that the 250Hz filter
is ideal for recovering weak ones and for 20M during RTTY
contests. The dual
passband filter fits very nicely within it. I don't care what
bandwidth you call it. Don't eliminate it as a choice.
I was astounded the
AGC pumping terribly since it's default roofing
filter is at more than 10 khz and K3 is at 2.7khz.
That's what my Argo V did.
The point is, the stock K3 setup is majorly robust for
either the main receiver or the subRx in stock form.
[Elecraft] K3: KRX3 question
Don Wilhelm w3fpr
I find that the narrower filters take out a lot of the noise before it
hits the DSP and it can even make just rag chew conditions nicer in my
very electrically noisy area. Actually I'm quite excited that once I
get my K3 back that I can set the 250Hz filter to be able to use it up
at 350. I even
I note in the new KRX3 manual the comment that diversity reception may be
enhanced by using filters with matched offsets for the main and sub-receivers.
I'm a 160M nut and this is certainly an important point to me... I have
these filterson backorder:
KFL3A-2002 K3 200 Hz, 5
Tom Whiteside wrote:
I note in the new KRX3 manual the comment that diversity reception may be
enhanced by using filters with matched offsets for the main and
sub-receivers.I'm a 160M nut and this is certainly an important point
to me... I have these filterson backorder:
H Tom,
We will match the 5 pole filters (to within 40 Hz) on request. If your
filters are already that close you are in good shape. We can't guarantee
a good enough yield on filter offsets to get closer than that, though
most will be closer. Fortunately 40 Hz is more than adequate as you can
Eric - WA6HHQ wrote:
H Tom,
We will match the 5 pole filters (to within 40 Hz) on request. If your
filters are already that close you are in good shape. We can't guarantee
a good enough yield on filter offsets to get closer than that, though
most will be closer. Fortunately 40 Hz is
Thanks Bill.I like the 5 poles for the reasons you stated recommending them
way back when.I ordered the ones you spec'd based on the idea of covering
the octaves... I agree that the narrow ones are for more extreme situations
but figured for $30 I'd get the narrow ones matched as
So am I to assume that the 8-pole filters are not going to need to worry
about this as they are all at 0 anyway? What is the advantage of
getting two matched pairs of 5-pole filters when you can get two 8-poles
for only 10 bucks a filter more?
I'm assuming that its 100 + 100 + 30 for matched
Thanks, Eric, for the update. This is exactly the kind of info I was
hoping for from Elecraft on the diversity filter issue. Now I can
complete the process of finalizing my RX3 and filter order to
complement my existing 5 pole filters. The $30 fee for matching to
the offsets I already
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