[Elecraft] 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: w8zn at comcast.net
>>    To: elecraft at 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
>>
>>