S meters in the USA
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Argh....what a nit-picker's delight.
The reason why you get "You're S9 but please repeat everything" is that you can be S9 and be covered by QRM/QRN. Check out what the ARRL says about RST (page 2 of the document). NOTHING about volts. It's all subjective. http://www.arrl.org/FandES/field/forms/fsd220.pdf For me the purpose of an S meter is as a RELATIVE comparison tool. This is ham radio, not a laboratory test bench. Who care what the S meter says? If you can carry on the QSO or exchange, S1 is as good as 30 over. If someone wants to check ant A vs ant B or station A vs station B, then all they really want to know is "which/who is louder." If they want real measurements, then the person on the receiving end should use a calibrated step attenuator and use it to "match" signal levels. But no ham is likely to ask someone else for "an accurate measure in uv or dbm" unless they already know that the "other guy" has a REAL means of measuring AND has real reason to want to know. For most of us hams (99.9%), "stronger" and "weaker" is good enough for comparisons that we might want to do. Sun is up...off to Dayton. CUL de Doug KR2Q _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: S meters in the USA
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DOUGLAS ZWIEBEL <[hidden email]> wrote: > Argh....what a nit-picker's delight. Quite right!! > The reason why you get "You're S9 but please repeat everything" is > that you can be S9 and be covered by QRM/QRN. I should have said 5 9. > If they want real measurements, then the person on the receiving end > should use a calibrated step attenuator and use it to "match" signal > levels. But no ham is likely to ask someone else for "an accurate > measure in uv or dbm" unless they already know that the "other guy" > has a REAL means of measuring AND has real reason to want to know. > For most of us hams (99.9%), "stronger" and "weaker" is good enough > for comparisons that we might want to do. True. I very seldom look at my S meter - calibrated in dbm - unless doing something with my antenna or if the other guy asks for a comparison in db. > Sun is up...off to Dayton. Enjoy yourself! 73, Geoff GM4ESD _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by DOUGLAS ZWIEBEL
> Check out what the ARRL says about RST (page 2 of the document).
> NOTHING about volts. It's all subjective. > > http://www.arrl.org/FandES/field/forms/fsd220.pdf A definition from the 1930s when one could not expect anything better. There is a better definition now (IARU Region 1 Technical Recommendation R.1) and it should imho be used. RST should be more than "Raten, Schätzen, Täuschen" > For me the purpose of an S meter is as a RELATIVE comparison tool. As long as the quality of the meters is as poor as most are, they are not even usable for relative comparisons excepting "stronger/weaker but absolutely no idea how much more or less". One should not expect a S-Meter to replace a R&S ESU test receiver, but they should be more than "feel good" meters. How can any regulator can take an interference report using S-Meter values seriously is beyond me, when one considers the current state of most meters. vy 73 de toby PS: raten = to guess, schätzen = to approximate, täuschen = to delude -- DD5FZ, 4N6FZ (ex dj7mgq, dg5mgq, dd5fz) K2 #885, K2/100 #3248 K3/100 #??? (< #200) DOK C12, BCC, DL-QRP-AG _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Geoffrey Mackenzie-Kennedy-2
How about bringing back the 6U5 Tuning eye.
----- Original Message ----- From: "Geoffrey Mackenzie-Kennedy" <[hidden email]> To: "DOUGLAS ZWIEBEL" <[hidden email]> Cc: "Elecraft Discussion List" <[hidden email]> Sent: Thursday, May 17, 2007 6:32 AM Subject: Re: [Elecraft] S meters in the USA > > DOUGLAS ZWIEBEL <[hidden email]> wrote: > >> Argh....what a nit-picker's delight. > > Quite right!! > >> The reason why you get "You're S9 but please repeat everything" is >> that you can be S9 and be covered by QRM/QRN. > > I should have said 5 9. > >> If they want real measurements, then the person on the receiving end >> should use a calibrated step attenuator and use it to "match" signal >> levels. But no ham is likely to ask someone else for "an accurate >> measure in uv or dbm" unless they already know that the "other guy" >> has a REAL means of measuring AND has real reason to want to know. >> For most of us hams (99.9%), "stronger" and "weaker" is good enough >> for comparisons that we might want to do. > > True. I very seldom look at my S meter - calibrated in dbm - unless doing > something with my antenna or if the other guy asks for a comparison in db. > >> Sun is up...off to Dayton. > > Enjoy yourself! > > 73, > Geoff > GM4ESD > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com > > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: S meters in the USA
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Now there's a thought :-)
73, Geoff GM4ESD Phillip Buckholdt <[hidden email]> wrote > How about bringing back the 6U5 Tuning eye. > _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: S meters in the USA
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Boy does that bring back memories! My first SW receiver, extracted from an old
upright radio/phono console in 1957, had one of those, and I'll never forget tuning in WWV for the very first time and watching the dark center narrow down to a slender wedge. And you could see the orange filament glowing behind the eye, too, which was pretty cool. :-) I would stare at that thing for hours as I listened. ( Maybe that's why I'm blind as a bat today...! ) Bill / W5WVO Geoffrey Mackenzie-Kennedy wrote: > Now there's a thought :-) > > 73, > Geoff > GM4ESD > > Phillip Buckholdt <[hidden email]> wrote > >> How about bringing back the 6U5 Tuning eye. >> > > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Phillip Buckholdt
On Thu, 17 May 2007, Phillip Buckholdt wrote:
> How about bringing back the 6U5 Tuning eye. Ah...great memories....as a kid, when we spent time at the "shore", the owner of the house had one of those beautiful console floor model radios....I was a tinkerer, and used the tuning eye to determine which one f the wires I had around the place got the strongest signal. Still remember the "eye", and then years later one stared at me out of the 20A exciter with the ARC-5 vfo. Thom www.baltimorehon.com/ Home of the Baltimore Lexicon www.tlchost.net/hosting/ Web Hosting as low as 3.49/month _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by DOUGLAS ZWIEBEL
In a message dated 5/17/2007 5:56:25 AM Pacific Daylight Time,
[hidden email] writes: > Now there's a thought :-) > > 73, > Geoff > GM4ESD > > Phillip Buckholdt <[hidden email]> wrote > > >How about bringing back the 6U5 Tuning eye. Here's an even scarier visual: A K3 with two of them -- one for each receiver. :-) Rob KC6ROC K2 #5924 (yes, it's almost done) _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by dj7mgq
An S-meter by itself is pretty useless for comparative measurements, but
it's easy to calibrate! A simple check with a step attenuator (e.g. Elecraft AT1) in the receive antenna line will show one how may dB/S-unit the meter indicates. With an Elecraft XG1 (or equivalent) signal generator it's easy to do the calibration in dBm or uV. For more accurate comparative work, putting the step attenuator in the line then adjusting the attenuation to match the original meter reading is a good way to tell another station how much their signal increased or decreased.(1) The bottom line is that trying to do comparative measurements for another station within 3 or 6 dB is pretty hard under most conditions. Slow AGC gives many signals the appearance of being quite stable when in fact they aren't: you're really seeing an average over time that may disguise a slow but steady drift upwards or downwards in strength. Fast AGC is needed for most checks, and then the S-meter often starts to "dance". There's a reason why S-units are about 6 dB. It is true that under quiet laboratory conditions a person with normal hearing can just discern a change in sound level of one dB, but when listening to a typical on-air signal on HF or MF, communications engineers long ago agreed that it's almost impossible to detect a change of less than 3 dB due to background noise, QSB, etc. That's a 2:1 power difference; under ideal conditions one has to double one's power or cut it in half to expect the other station to notice any difference at all! So twice that, 6 dB, seemed a good definition for an S-unit since S-units are defined by the perception of the person listening, not an absolute numerical scale. As Toby mentioned, that definition has been adopted by the IARU: "At the IARU Region 1 Conference in Hungary 1978 the need for a harmonised standard for the 'S-meter scale' was expressed and a proposal was accepted for publication in society journals. The essential recommendation was 1 S point is 6 dB. At the Brighton Conference in 1981 the recommendation was formally adopted as a standard for amateur radio equipment manufacturers." (2) Only the S-9 level of 50 uV is mentioned in the K3 FAQ's, but I'd not be surprised to see the meter set up for 6dB/S-unit. Right now the FAQ's are vague about what happens when the preamp or attenuator are used. The K2, for example, does not compensate for this so the "S-meter" jumps up and down 10 to 20 dB depending upon the setting of the preamp or attenuator. Ron AC7AC (1) The best way to help out a buddy who wants comparative signal measurements is to connect a 'scope or sensitive a-c meter to the receiver audio output, turn the AGC OFF, and use the step attenuator in the RX antenna line. The audio voltage level is measured for reference. After the change is made at the far end, the attenuator is adjusted to reproduce the same audio voltage without touching any receiver controls! The attenuator will then show the actual change in signal level in dB as accurately as propagation conditions allows. Trying to do this with AGC on makes the change harder to see, since the AGC tries to level out the change as the signal strength varies. Long ago I disabled the AGC in my KX1 (a simple wire jumper that can be removed) so I could use it with my AT1 step attenuator as a sensitive RF voltmeter for just this sort of test on 80/40/30/20 meters. (2) http://thf.ref-union.org/6a.pdf _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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