K144XV receive gain

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K144XV receive gain

W8ZN
After seeing several postings about the K144xv gain and experiencing issues myself, I did some testing.

Comparing a K3/K144XV on 2m vs 6m.

On version 3.97 firmware, on 6m -87dbm yielded a S9 signal with the PR6 preamp in but the internal preamp off - best setting.
On 2m, this yielded a S9+5 signal with the internal preamp still off.

After loading 4.12 or higher, the same -87dbm gave the same S9 on 6m but now only S5 on 2m and still only S7 with the internal preamp on. To achieve the same S9 reading, I had to increase the signal level to -72dbm with the internal preamp off. The release notes for 4.12 reference a gain change on the K144xv and by the results of the 3.97 test I agree, there was too much gain but instead of dropping 6 db or so, it appears that they dropped 15db. Hopefully this will be rectified in the near future.



Terry Price - W8ZN  ex K8ISK
FM18dv - 1.8MHz thru 47GHz
K8GP - The Grid Pirates - FM19bb
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Re: K144XV receive gain

Jeff Cochrane - VK4XA
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Re: K144XV receive gain

N6JW
I can certainly confirm this receive gain overcorrection problem on 2m.

The "cpu sleep on rx" upgrade really helped cut back on the birdies.  Thanks!

But the overcorrection of the 2m gain compensation stands out like a sore
thumb, particularly when one can actually see the relative amplitude of the
signal on the P3.  Of course, this is "just a small matter of programming!"
and I'm sure we will get it right in due course.

Thanks & 73

John, N6JW


Jeff Cochrane - VK4BOF wrote
Hi Terry,
Thanks very much for posting of those figures.
Although I do not have test gear that can back those numbers up I can say that from my extensive on air testing that indeed, the 2M gain reduction was overdone and to somewhere in the region your figures are showing.
The local (60+Km away) 2M FM repeater was normally S9+30db on earlier firmware releases (around release 3.97 or so) on my K3 and once I got to firmware revision 4.05 it had dropped to S9+5db, now that I am at revision 4.14 it is now S5!
Nothing has changed at the repeater and all other radios tried with the same antenna at my location show at least S9+20db signal strength. (And usually full scale, it is an exceptional repeater, over 1500ft high and with 50watts output to a 6+db gain antenna, it is almost full scale on my handheld in the back yard here!)
Even allowing that the other radios have optomistic S meters I cannot believe that they are all out by so much and by such a consistant amount.

The overdoing of the 2m gain reduction has been the subject of a few emails I have sent to Elecraft and to this reflector and to date I have not heard an answer on the subject.

Jeff Cochrane - VK4BOF
Innisfail, QLD, Australia
Elecraft K3# 4257

  ----- Original Message -----
  From: w8zn@comcast.net
  To: elecraft@mailman.qth.net
  Sent: Wednesday, November 10, 2010 11:18 AM
  Subject: [Elecraft] K144XV receive gain


  After seeing several postings about the K144xv gain and experiencing issues myself, I did some testing.

  Comparing a K3/K144XV on 2m vs 6m.

  On version 3.97 firmware, on 6m -87dbm yielded a S9 signal with the PR6 preamp in but the internal preamp off - best setting. On 2m, this yielded a S9+5 signal with the internal preamp still off.

  After loading 4.12 or higher, the same -87dbm gave the same S9 on 6m but now only S5 on 2m and still only S7 with the internal preamp on. To achieve the same S9 reading, I had to increase the signal level to -72dbm with the internal preamp off. The release notes for 4.12 reference a gain change on the K144xv and by the results of the 3.97 test I agree, there was too much gain but instead of dropping 6 db or so, it appears that they dropped 15db. Hopefully this will be rectified in the near future.

  Terry Price - W8ZN  ex K8ISK
 
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Re: K144XV receive gain

Alexandr Kobranov

Keep in mind that on VHF and up S9 on S-meter is by definition as
-93dBm on input (5uV) - it is 20dB difference from HF bands.
I suppose it is respected for K3/P3 K144XV setup.
Are there some exact valus (MDS, NF, S9 level) for old and new
firmware versions? Maybe I missed them, let me know out of list in
such case...

73!

Lexa, OK1DST
K3/100 #727




Dne 10.11.2010 4:55, N6JW napsal(a):

>
> I can certainly confirm this receive gain overcorrection problem on 2m.
>
> The "cpu sleep on rx" upgrade really helped cut back on the birdies.
> Thanks!
>
> But the overcorrection of the 2m gain compensation stands out like a sore
> thumb, particularly when one can actually see the relative amplitude of the
> signal on the P3.  Of course, this is "just a small matter of programming!"
> and I'm sure we will get it right in due course.
>
> Thanks&  73
>
> John, N6JW
>
>
>
> Jeff Cochrane - VK4BOF wrote:
>>
>> Hi Terry,
>> Thanks very much for posting of those figures.
>> Although I do not have test gear that can back those numbers up I can say
>> that from my extensive on air testing that indeed, the 2M gain reduction
>> was overdone and to somewhere in the region your figures are showing.
>> The local (60+Km away) 2M FM repeater was normally S9+30db on earlier
>> firmware releases (around release 3.97 or so) on my K3 and once I got to
>> firmware revision 4.05 it had dropped to S9+5db, now that I am at revision
>> 4.14 it is now S5!
>> Nothing has changed at the repeater and all other radios tried with the
>> same antenna at my location show at least S9+20db signal strength. (And
>> usually full scale, it is an exceptional repeater, over 1500ft high and
>> with 50watts output to a 6+db gain antenna, it is almost full scale on my
>> handheld in the back yard here!)
>> Even allowing that the other radios have optomistic S meters I cannot
>> believe that they are all out by so much and by such a consistant amount.
>>
>> The overdoing of the 2m gain reduction has been the subject of a few
>> emails I have sent to Elecraft and to this reflector and to date I have
>> not heard an answer on the subject.
>>
>> Jeff Cochrane - VK4BOF
>> Innisfail, QLD, Australia
>> Elecraft K3# 4257
>>
>>    ----- Original Message -----
>>    From: [hidden email]
>>    To: [hidden email]
>>    Sent: Wednesday, November 10, 2010 11:18 AM
>>    Subject: [Elecraft] K144XV receive gain
>>
>>
>>    After seeing several postings about the K144xv gain and experiencing
>> issues myself, I did some testing.
>>
>>    Comparing a K3/K144XV on 2m vs 6m.
>>
>>    On version 3.97 firmware, on 6m -87dbm yielded a S9 signal with the PR6
>> preamp in but the internal preamp off - best setting. On 2m, this yielded
>> a S9+5 signal with the internal preamp still off.
>>
>>    After loading 4.12 or higher, the same -87dbm gave the same S9 on 6m but
>> now only S5 on 2m and still only S7 with the internal preamp on. To
>> achieve the same S9 reading, I had to increase the signal level to -72dbm
>> with the internal preamp off. The release notes for 4.12 reference a gain
>> change on the K144xv and by the results of the 3.97 test I agree, there
>> was too much gain but instead of dropping 6 db or so, it appears that they
>> dropped 15db. Hopefully this will be rectified in the near future.
>>
>>    Terry Price - W8ZN  ex K8ISK
>>
>>
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Re: K144XV receive gain

David Pratt
I accept that, Lexa, but it does just seem strange that an audibly
strong signal on 2 metres, with very little background noise, hardly
moves the S-meter. It's quite okay on the HF bands and 6 metres.

73 de David G4DMP

In a recent message, Alexandr Kobranov <[hidden email]> writes
>
>Keep in mind that on VHF and up S9 on S-meter is by definition as
>-93dBm on input (5uV) - it is 20dB difference from HF bands.
>I suppose it is respected for K3/P3 K144XV setup.
>Are there some exact valus (MDS, NF, S9 level) for old and new
>firmware versions?



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Re: K144XV receive gain

Alexandr Kobranov
In reply to this post by Alexandr Kobranov
Yes, in case you will add 20dB in firmware - now it seems to be as lowered.
(if MDS and NF stays the same).
Simply if anybody can inject -93dBm on 144MHz and report S-meter
reading - this will be useful and more valid report.

73!
L. -dst-


2010/11/10 Dale Parfitt <[hidden email]>:

>
> ----- Original Message ----- From: "Alexandr Kobranov" <[hidden email]>
> Cc: <[hidden email]>
> Sent: Wednesday, November 10, 2010 3:58 AM
> Subject: Re: [Elecraft] K144XV receive gain
>
>
>>
>> Keep in mind that on VHF and up S9 on S-meter is by definition as
>> -93dBm on input (5uV) - it is 20dB difference from HF bands.
>> I suppose it is respected for K3/P3 K144XV setup.
>> Are there some exact valus (MDS, NF, S9 level) for old and new
>> firmware versions? Maybe I missed them, let me know out of list in
>> such case...
>>
>> 73!
>>
>> Lexa, OK1DST
>> K3/100 #727
>>
>>
> If that is the case, then the S meter would be even more sensitive than on
> HF.
>
> Dale W4OP
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Re: K144XV receive gain

Don Nelson
In reply to this post by Alexandr Kobranov
Hi all,

I know this is a nit.

But the IARU state that the S9 signal level is -93 dBm for frequencies
above 144 MHz. I for one did not know that the -73 dBm was only valid
for lower bands until taking a look at the IARU recommendations. To me
the IARU states that the -93 dBm is valid above the whole 2m band and
therefore does not include the 2m band.

The IARU recommendation R.1 is found at web page
http://www.algonet.se/~k-jarl/ssa/IARU/smeter.html.

Another reference is at
http://webpages.charter.net/dig2bn/RF%20Comm-Elec%20Course%20Student%20Study%20Guides/S-Meter%20Calibration%20&%20IARU%20Standards.pdf 
<http://webpages.charter.net/dig2bn/RF%20Comm-Elec%20Course%20Student%20Study%20Guides/S-Meter%20Calibration%20&%20IARU%20Standards.pdf>

Don, N0YE







On 11/10/2010 1:58 AM, Alexandr Kobranov wrote:

> Keep in mind that on VHF and up S9 on S-meter is by definition as
> -93dBm on input (5uV) - it is 20dB difference from HF bands.
> I suppose it is respected for K3/P3 K144XV setup.
> Are there some exact valus (MDS, NF, S9 level) for old and new
> firmware versions? Maybe I missed them, let me know out of list in
> such case...
>
> 73!
>
> Lexa, OK1DST
> K3/100 #727
>
>
>
>
> Dne 10.11.2010 4:55, N6JW napsal(a):
>> I can certainly confirm this receive gain overcorrection problem on 2m.
>>
>> The "cpu sleep on rx" upgrade really helped cut back on the birdies.
>> Thanks!
>>
>> But the overcorrection of the 2m gain compensation stands out like a sore
>> thumb, particularly when one can actually see the relative amplitude of the
>> signal on the P3.  Of course, this is "just a small matter of programming!"
>> and I'm sure we will get it right in due course.
>>
>> Thanks&   73
>>
>> John, N6JW
>>
>>
>>
>> Jeff Cochrane - VK4BOF wrote:
>>> Hi Terry,
>>> Thanks very much for posting of those figures.
>>> Although I do not have test gear that can back those numbers up I can say
>>> that from my extensive on air testing that indeed, the 2M gain reduction
>>> was overdone and to somewhere in the region your figures are showing.
>>> The local (60+Km away) 2M FM repeater was normally S9+30db on earlier
>>> firmware releases (around release 3.97 or so) on my K3 and once I got to
>>> firmware revision 4.05 it had dropped to S9+5db, now that I am at revision
>>> 4.14 it is now S5!
>>> Nothing has changed at the repeater and all other radios tried with the
>>> same antenna at my location show at least S9+20db signal strength. (And
>>> usually full scale, it is an exceptional repeater, over 1500ft high and
>>> with 50watts output to a 6+db gain antenna, it is almost full scale on my
>>> handheld in the back yard here!)
>>> Even allowing that the other radios have optomistic S meters I cannot
>>> believe that they are all out by so much and by such a consistant amount.
>>>
>>> The overdoing of the 2m gain reduction has been the subject of a few
>>> emails I have sent to Elecraft and to this reflector and to date I have
>>> not heard an answer on the subject.
>>>
>>> Jeff Cochrane - VK4BOF
>>> Innisfail, QLD, Australia
>>> Elecraft K3# 4257
>>>
>>>     ----- Original Message -----
>>>     From: [hidden email]
>>>     To: [hidden email]
>>>     Sent: Wednesday, November 10, 2010 11:18 AM
>>>     Subject: [Elecraft] K144XV receive gain
>>>
>>>
>>>     After seeing several postings about the K144xv gain and experiencing
>>> issues myself, I did some testing.
>>>
>>>     Comparing a K3/K144XV on 2m vs 6m.
>>>
>>>     On version 3.97 firmware, on 6m -87dbm yielded a S9 signal with the PR6
>>> preamp in but the internal preamp off - best setting. On 2m, this yielded
>>> a S9+5 signal with the internal preamp still off.
>>>
>>>     After loading 4.12 or higher, the same -87dbm gave the same S9 on 6m but
>>> now only S5 on 2m and still only S7 with the internal preamp on. To
>>> achieve the same S9 reading, I had to increase the signal level to -72dbm
>>> with the internal preamp off. The release notes for 4.12 reference a gain
>>> change on the K144xv and by the results of the 3.97 test I agree, there
>>> was too much gain but instead of dropping 6 db or so, it appears that they
>>> dropped 15db. Hopefully this will be rectified in the near future.
>>>
>>>     Terry Price - W8ZN  ex K8ISK
>>>
>>>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
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Re: K144XV receive gain

Alan Bloom
> To me
> the IARU states that the -93 dBm is valid above the whole 2m band and
> therefore does not include the 2m band.

I scratched my head over that one.  Then I looked again at the IARU's
wording and I think I see what you mean:

"3. On the bands above 144 MHz this available power shall be -93 dBm, "

If they had said "On the bands above the 144 MHz BAND ..." then I would
agree with you, but I think it's clear that they intended that 144-148
MHz be included in "the bands above 144 MHz".

The bigger question is what to do about the 50 MHz band.  The IARU
recommendation specifies:

"2. On the bands below 30 MHz a meter deviation of S-9 corresponds to an
available power of -73 dBm ..."

but does not say what to do between 30 and 144 MHz.  I have seen it
stated that most people assume it should be -93 dBm because 50 MHz is a
VHF band, but AFIK it's not official.

Alan


On Wed, 2010-11-10 at 09:34 -0700, Don Nelson wrote:

> Hi all,
>
> I know this is a nit.
>
> But the IARU state that the S9 signal level is -93 dBm for frequencies
> above 144 MHz. I for one did not know that the -73 dBm was only valid
> for lower bands until taking a look at the IARU recommendations. To me
> the IARU states that the -93 dBm is valid above the whole 2m band and
> therefore does not include the 2m band.
>
> The IARU recommendation R.1 is found at web page
> http://www.algonet.se/~k-jarl/ssa/IARU/smeter.html.
>
> Another reference is at
> http://webpages.charter.net/dig2bn/RF%20Comm-Elec%20Course%20Student%20Study%20Guides/S-Meter%20Calibration%20&%20IARU%20Standards.pdf 
> <http://webpages.charter.net/dig2bn/RF%20Comm-Elec%20Course%20Student%20Study%20Guides/S-Meter%20Calibration%20&%20IARU%20Standards.pdf>
>
> Don, N0YE
>
>
>
>
>
>
>
> On 11/10/2010 1:58 AM, Alexandr Kobranov wrote:
> > Keep in mind that on VHF and up S9 on S-meter is by definition as
> > -93dBm on input (5uV) - it is 20dB difference from HF bands.
> > I suppose it is respected for K3/P3 K144XV setup.
> > Are there some exact valus (MDS, NF, S9 level) for old and new
> > firmware versions? Maybe I missed them, let me know out of list in
> > such case...
> >
> > 73!
> >
> > Lexa, OK1DST
> > K3/100 #727
> >
> >
> >
> >
> > Dne 10.11.2010 4:55, N6JW napsal(a):
> >> I can certainly confirm this receive gain overcorrection problem on 2m.
> >>
> >> The "cpu sleep on rx" upgrade really helped cut back on the birdies.
> >> Thanks!
> >>
> >> But the overcorrection of the 2m gain compensation stands out like a sore
> >> thumb, particularly when one can actually see the relative amplitude of the
> >> signal on the P3.  Of course, this is "just a small matter of programming!"
> >> and I'm sure we will get it right in due course.
> >>
> >> Thanks&   73
> >>
> >> John, N6JW
> >>
> >>
> >>
> >> Jeff Cochrane - VK4BOF wrote:
> >>> Hi Terry,
> >>> Thanks very much for posting of those figures.
> >>> Although I do not have test gear that can back those numbers up I can say
> >>> that from my extensive on air testing that indeed, the 2M gain reduction
> >>> was overdone and to somewhere in the region your figures are showing.
> >>> The local (60+Km away) 2M FM repeater was normally S9+30db on earlier
> >>> firmware releases (around release 3.97 or so) on my K3 and once I got to
> >>> firmware revision 4.05 it had dropped to S9+5db, now that I am at revision
> >>> 4.14 it is now S5!
> >>> Nothing has changed at the repeater and all other radios tried with the
> >>> same antenna at my location show at least S9+20db signal strength. (And
> >>> usually full scale, it is an exceptional repeater, over 1500ft high and
> >>> with 50watts output to a 6+db gain antenna, it is almost full scale on my
> >>> handheld in the back yard here!)
> >>> Even allowing that the other radios have optomistic S meters I cannot
> >>> believe that they are all out by so much and by such a consistant amount.
> >>>
> >>> The overdoing of the 2m gain reduction has been the subject of a few
> >>> emails I have sent to Elecraft and to this reflector and to date I have
> >>> not heard an answer on the subject.
> >>>
> >>> Jeff Cochrane - VK4BOF
> >>> Innisfail, QLD, Australia
> >>> Elecraft K3# 4257
> >>>
> >>>     ----- Original Message -----
> >>>     From: [hidden email]
> >>>     To: [hidden email]
> >>>     Sent: Wednesday, November 10, 2010 11:18 AM
> >>>     Subject: [Elecraft] K144XV receive gain
> >>>
> >>>
> >>>     After seeing several postings about the K144xv gain and experiencing
> >>> issues myself, I did some testing.
> >>>
> >>>     Comparing a K3/K144XV on 2m vs 6m.
> >>>
> >>>     On version 3.97 firmware, on 6m -87dbm yielded a S9 signal with the PR6
> >>> preamp in but the internal preamp off - best setting. On 2m, this yielded
> >>> a S9+5 signal with the internal preamp still off.
> >>>
> >>>     After loading 4.12 or higher, the same -87dbm gave the same S9 on 6m but
> >>> now only S5 on 2m and still only S7 with the internal preamp on. To
> >>> achieve the same S9 reading, I had to increase the signal level to -72dbm
> >>> with the internal preamp off. The release notes for 4.12 reference a gain
> >>> change on the K144xv and by the results of the 3.97 test I agree, there
> >>> was too much gain but instead of dropping 6 db or so, it appears that they
> >>> dropped 15db. Hopefully this will be rectified in the near future.
> >>>
> >>>     Terry Price - W8ZN  ex K8ISK
> >>>
> >>>
> > ______________________________________________________________
> > Elecraft mailing list
> > Home: http://mailman.qth.net/mailman/listinfo/elecraft
> > Help: http://mailman.qth.net/mmfaq.htm
> > Post: mailto:[hidden email]
> >
> > This list hosted by: http://www.qsl.net
> > Please help support this email list: http://www.qsl.net/donate.html
> >
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html


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Re: K144XV receive gain

Alexandr Kobranov
In reply to this post by Don Nelson
Hi Don,
thanks for discussion entry!

What is stated in IARU document is
"On the bands above 144 MHz this available power shall be -93 dBm"

I am afraid that "above 144" means above 144.000 let say 144.010 etc.

In one link you sent (thanks!) there is written:

"For the VHF / UHF bands, an ‘S9’ signal strength is a receiver input
power of ‘-93 dBm’. This is a level of ‘5mV’ in 50W at the receiver's
antenna input assuming the input impedance of the receiver is 50W."

No doubts (on my side) 144MHz band is VHF ;-)

My comment was mainly about what level correspond S9 on K3/K144XV now
and then what level should be as S9. And if this "gain" problem is
really lower gain or onky S-levels interpretation problem.
That´s it, hope somebody will report some real measured values.

73!
Lexa,  -dst-


2010/11/10 Don Nelson <[hidden email]>:

> Hi all,
>
> I know this is a nit.
>
> But the IARU state that the S9 signal level is -93 dBm for frequencies
> above 144 MHz. I for one did not know that the -73 dBm was only valid
> for lower bands until taking a look at the IARU recommendations. To me
> the IARU states that the -93 dBm is valid above the whole 2m band and
> therefore does not include the 2m band.
>
> The IARU recommendation R.1 is found at web page
> http://www.algonet.se/~k-jarl/ssa/IARU/smeter.html.
>
> Another reference is at
> http://webpages.charter.net/dig2bn/RF%20Comm-Elec%20Course%20Student%20Study%20Guides/S-Meter%20Calibration%20&%20IARU%20Standards.pdf
> <http://webpages.charter.net/dig2bn/RF%20Comm-Elec%20Course%20Student%20Study%20Guides/S-Meter%20Calibration%20&%20IARU%20Standards.pdf>
>
> Don, N0YE
>
>
>
>
>
>
>
> On 11/10/2010 1:58 AM, Alexandr Kobranov wrote:
>> Keep in mind that on VHF and up S9 on S-meter is by definition as
>> -93dBm on input (5uV) - it is 20dB difference from HF bands.
>> I suppose it is respected for K3/P3 K144XV setup.
>> Are there some exact valus (MDS, NF, S9 level) for old and new
>> firmware versions? Maybe I missed them, let me know out of list in
>> such case...
>>
>> 73!
>>
>> Lexa, OK1DST
>> K3/100 #727
>>
>>
>>
>>
>> Dne 10.11.2010 4:55, N6JW napsal(a):
>>> I can certainly confirm this receive gain overcorrection problem on 2m.
>>>
>>> The "cpu sleep on rx" upgrade really helped cut back on the birdies.
>>> Thanks!
>>>
>>> But the overcorrection of the 2m gain compensation stands out like a sore
>>> thumb, particularly when one can actually see the relative amplitude of the
>>> signal on the P3.  Of course, this is "just a small matter of programming!"
>>> and I'm sure we will get it right in due course.
>>>
>>> Thanks&   73
>>>
>>> John, N6JW
>>>
>>>
>>>
>>> Jeff Cochrane - VK4BOF wrote:
>>>> Hi Terry,
>>>> Thanks very much for posting of those figures.
>>>> Although I do not have test gear that can back those numbers up I can say
>>>> that from my extensive on air testing that indeed, the 2M gain reduction
>>>> was overdone and to somewhere in the region your figures are showing.
>>>> The local (60+Km away) 2M FM repeater was normally S9+30db on earlier
>>>> firmware releases (around release 3.97 or so) on my K3 and once I got to
>>>> firmware revision 4.05 it had dropped to S9+5db, now that I am at revision
>>>> 4.14 it is now S5!
>>>> Nothing has changed at the repeater and all other radios tried with the
>>>> same antenna at my location show at least S9+20db signal strength. (And
>>>> usually full scale, it is an exceptional repeater, over 1500ft high and
>>>> with 50watts output to a 6+db gain antenna, it is almost full scale on my
>>>> handheld in the back yard here!)
>>>> Even allowing that the other radios have optomistic S meters I cannot
>>>> believe that they are all out by so much and by such a consistant amount.
>>>>
>>>> The overdoing of the 2m gain reduction has been the subject of a few
>>>> emails I have sent to Elecraft and to this reflector and to date I have
>>>> not heard an answer on the subject.
>>>>
>>>> Jeff Cochrane - VK4BOF
>>>> Innisfail, QLD, Australia
>>>> Elecraft K3# 4257
>>>>
>>>>     ----- Original Message -----
>>>>     From: [hidden email]
>>>>     To: [hidden email]
>>>>     Sent: Wednesday, November 10, 2010 11:18 AM
>>>>     Subject: [Elecraft] K144XV receive gain
>>>>
>>>>
>>>>     After seeing several postings about the K144xv gain and experiencing
>>>> issues myself, I did some testing.
>>>>
>>>>     Comparing a K3/K144XV on 2m vs 6m.
>>>>
>>>>     On version 3.97 firmware, on 6m -87dbm yielded a S9 signal with the PR6
>>>> preamp in but the internal preamp off - best setting. On 2m, this yielded
>>>> a S9+5 signal with the internal preamp still off.
>>>>
>>>>     After loading 4.12 or higher, the same -87dbm gave the same S9 on 6m but
>>>> now only S5 on 2m and still only S7 with the internal preamp on. To
>>>> achieve the same S9 reading, I had to increase the signal level to -72dbm
>>>> with the internal preamp off. The release notes for 4.12 reference a gain
>>>> change on the K144xv and by the results of the 3.97 test I agree, there
>>>> was too much gain but instead of dropping 6 db or so, it appears that they
>>>> dropped 15db. Hopefully this will be rectified in the near future.
>>>>
>>>>     Terry Price - W8ZN  ex K8ISK
>>>>
>>>>
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Re: K144XV receive gain

Eric Swartz - WA6HHQ
Administrator
Its only an S-Meter calibration issue when using the K144XV, not a
receive gain issue.

73, Eric   WA6HHQ
www.elecraft.com
---

On 11/10/2010 12:32 PM, Alexandr Kobranov wrote:
> ...
>
> My comment was mainly about what level correspond S9 on K3/K144XV now
> and then what level should be as S9. And if this "gain" problem is
> really lower gain or onky S-levels interpretation problem.
> That´s it, hope somebody will report some real measured values.
>
> 73!
> Lexa,  -dst-
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Re: K144XV receive gain

Alexandr Kobranov
Thanks Eric,

just discovered this your statement in another thread,

thanks!

73!
L. -dst-


2010/11/10 Eric Swartz - WA6HHQ, Elecraft <[hidden email]>:

> Its only an S-Meter calibration issue when using the K144XV, not a receive
> gain issue.
>
> 73, Eric   WA6HHQ
> www.elecraft.com
> ---
>
> On 11/10/2010 12:32 PM, Alexandr Kobranov wrote:
>>
>> ...
>>
>> My comment was mainly about what level correspond S9 on K3/K144XV now
>> and then what level should be as S9. And if this "gain" problem is
>> really lower gain or onky S-levels interpretation problem.
>> That´s it, hope somebody will report some real measured values.
>>
>> 73!
>> Lexa,  -dst-
>
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Re: K144XV receive gain

W8ZN
In reply to this post by W8ZN
I've done extensive testing and Eric confirmed that the gain is fixed, only the s-meter reading is adjustable via firmware. I tested a K3/K144XV on 3.97 and again at 4.14 and the sensitivty is the same (quite good I might add!!!!), only the s-meter reading has changed.

Terry - W8ZN
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