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 <[email protected]>: > 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: [email protected] >>>> To: [email protected] >>>> 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:[email protected] >> >> 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:[email protected] > > 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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
