Marconi testing the Sigma4 vs. Gain Master

[bob85]

the s-meter on many radios does indeed use the agc circuit,

in most exports it works by rectifying a sample of rf from receivers IF stages, next it is amplified through the agc buffer amp,
the agc buffer / agc amp and squelch amp are usually each one section of a quad opamp but not always,
output from the agc buffer is sent to the s-meter through a resistive divider or two dividers if it has ssb and am/fm s-meter adjustments and agc timing is changed according to mode,
the agc buffer signal also goes through the RC components that set agc attack and decay timing then onto the agc amplifier to control receiver gain,
the squelch amp also takes its signal from the agc buffer

 

[jazzsinger]

Jazz I think your gonna have to change what you said about AGC having nothing to do with S Meter. A basic S meter works by measuring the agc voltage.

i appreciate what your saying, i may have worded it badly,its early morning here and i'm tired and gagging for a spliff,lol. i think the technical term for that is my ass is strung out.

the point i was making was yes the s meter may derive its driving voltage from the agc loop, but it has very little effect on s meter readings compared to the effect the agc has on the gain of the if/af stages where it levels audio over a wide range of signal strengths,

it doesn't level s meter reading to anywhere near the same degree or as i said all signals within the s meter range would show only a slight fluctuation in readings in the same way the audio shows only slight variation within the agc range, which obviously isn't the case.

anyway its bedtime here,good night,good morning or good afternoon to everyone wherever in the world you may be.

 

[MrSuburban]

the s-meter on many radios does indeed use the agc circuit,

in most exports it works by rectifying a sample of rf from receivers IF stages, next it is amplified through the agc buffer amp,
the agc buffer / agc amp and squelch amp are usually each one section of a quad opamp but not always,
output from the agc buffer is sent to the s-meter through a resistive divider or two dividers if it has ssb and am/fm s-meter adjustments and agc timing is changed according to mode,
the agc buffer signal also goes through the RC components that set agc attack and decay timing then onto the agc amplifier to control receiver gain,
the squelch amp also takes its signal from the agc buffer

Well well look who woke up.

 

[Marconi]

Well well look who woke up.

Well MrS, whatever the deal is I mentioned about the AGC came for Mr. Well Awake himself sometime back...as I stumbled around in ignorance trying to compare antennas. I found I was asking myself the question of "WHY" when I should have been concentrating on the question "what if?"

It doesn't ruffle my feathers at all for guys to disagree with me as long as they keep the personal out of the mix, because more often than not I learn more when paying close attention---as apposed to getting all flustered and not paying attention to anything but my own ego and seeing who can outlast the other in disagreement---which has nothing at all to do with good constructive argument.

Anyway MrS, here is a video of trying a low signal hoping to bypass the possible affects of the AGC at my location. I did this one on my Galaxy 2547 just because it has an analog meter. In thinking about how I could improve on side by side comparisons, I also am considering using my TS570's dual input to indicate the switching rather than verbalize as I use the switch box. That way I don't have to talk so much, and cover what is going on for the video. I know my comments are necessary to help explain, but I realize it does interfere with the viewers perspective a bit, plus I can hardly walk and chew gum at the same time and that is why I misspeak and have to correct.

YouTube - Marconi using a low signal contact comparing his GM vs. Sigma4

I am almost thru with my Signal Report on paper that reflects my observations during on-air testing of the two this AM. A while later I even had a chance to do some DX reports comparing while the local traffic was still in my receiver as it was just moments earlier. I didn't record anything on paper or video, but I'm be giving y'all the new and improved "Yoda" "Coolbreeze" style of report, I'll be calling the;

"Anecdotal Signal Report Only"​

short and to the point accounts with little or no reliable work,
stories and lies from the swamp​

 

[MrSuburban]

Well MrS, whatever the deal is I mentioned about the AGC came for Mr. Well Awake himself sometime back...as I stumbled around in ignorance trying to compare antennas. I found I was asking myself the question of "WHY" when I should have been concentrating on the question "what if?"

It doesn't ruffle my feathers at all for guys to disagree with me as long as they keep the personal out of the mix, because more often than not I learn more when paying close attention---as apposed to getting all flustered and not paying attention to anything but my own ego and seeing who can outlast the other in disagreement---which has nothing at all to do with good constructive argument.

Anyway MrS, here is a video of trying a low signal hoping to bypass the possible affects of the AGC at my location. I did this one on my Galaxy 2547 just because it has an analog meter. In thinking about how I could improve on side by side comparisons, I also am considering using my TS570's dual input to indicate the switching rather than verbalize as I use the switch box. That way I don't have to talk so much, and cover what is going on for the video. I know my comments are necessary to help explain, but I realize it does interfere with the viewers perspective a bit, plus I can hardly walk and chew gum at the same time and that is why I misspeak and have to correct.

YouTube - Marconi using a low signal contact comparing his GM vs. Sigma4

I am almost thru with my Signal Report on paper that reflects my observations during on-air testing of the two this AM. A while later I even had a chance to do some DX reports comparing while the local traffic was still in my receiver as it was just moments earlier. I didn't record anything on paper or video, but I'm be giving y'all the new and improved "Yoda" "Coolbreeze" style of report, I'll be calling the;

"Anecdotal Signal Report Only"​

short and to the point accounts with little or no reliable work,
stories and lies from the swamp​

Good Video I think this clearly demonstrates at low signal there is a difference and you are able to tell the diffference, also notice in beginning of video the higher S reading when u switch not as drastic of change from one to othe antenna.

Now this can be because the Vector may work better with a distant signal and the effect of lower TOA doesnt make difference until further away. To me it is clear the Sigma was working better. You did fine with the way you did it, u were able to get a guy talking and switch to other while he is talking.

If you dont want to talk to much at beginning of video declare antenna 1 is = X antenna, # 2 = x then all you need to say is one or two after you switch we will know which antenna u mean. Otherwise this is a good test you made alot of points, used a radio with a meter we would be able to more see the difference, you got good low signal/distant stations where u will see difference in antennas. Thank You


Ps: did you happen to phase your coax maybe this is why you are seeing a difference now.:laugh:

 

[Marconi]

Good Video I think this clearly demonstrates at low signal there is a difference and you are able to tell the difference, also notice in beginning of video the higher S reading when u switch not as drastic of change from one to other antenna.

Now this can be because the Vector may work better with a distant signal and the effect of lower TOA doesnt make difference until further away. To me it is clear the Sigma was working better. You did fine with the way you did it, u were able to get a guy talking and switch to other while he is talking.

If you dont want to talk to much at beginning of video declare antenna 1 is = X antenna, # 2 = x then all you need to say is one or two after you switch we will know which antenna u mean. Otherwise this is a good test you made alot of points, used a radio with a meter we would be able to more see the difference, you got good low signal/distant stations where u will see difference in antennas. Thank You


Ps: did you happen to phase your coax maybe this is why you are seeing a difference now.:laugh:

Thanks MrS. Do you mean by phase, did I attempt to make the feed line length somewhere close to a resonant 1/2 wavelength multiple at some frequency? If so then NO!

These two lines are what I consider to be random lengths, @ 75' 7" on the GM and 56' 10" on the Sigma4. I recently measured them before I installed the antennas for this series.

View attachment Gain Master vs. Sigma4.pdf

BTW, I have a new video today using my TS570D's dual coax input so I can switch and the antenna number pops up on the video, either #1 or #2 just like you describe. I forget what is on the video, but I think it is more voice that will help to support the paper report above. I just wished the two-way reporting was on video, but I think I forgot to turn on the camera. I think this video is also on YouTube and may be at the top as my final video in this series.

 

[MrSuburban]

Thanks MrS. Do you mean by phase, did I attempt to make the feed line length somewhere close to a resonant 1/2 wavelength multiple at some frequency? If so then NO!

These two lines are what I consider to be random lengths, @ 75' 7" on the GM and 56' 10" on the Sigma4. I recently measured them before I installed the antennas for this series.

I was being facitous with the phasing of the coax

View attachment 4126

BTW, I have a new video today using my TS570D's dual coax input so I can switch and the antenna number pops up on the video, either #1 or #2 just like you describe. I forget what is on the video, but I think it is more voice that will help to support the paper report above. I just wished the two-way reporting was on video, but I think I forgot to turn on the camera. I think this video is also on YouTube and may be at the top as my final video in this series.

What sticks out to me on the galaxy the Sigma clearly had a advantage and you were able to discern a fairly signifigant change in S meter. Hooking up your Kenwood trying to notice the same difference with a bar graph meter now all of a sudden that advantage went away.

 

[Marconi]

I was being facitous with the phasing of the coax

Were you poking a finger in 007's eye with the reference to phasing where you were trying to be factious? Shame on ya'.

What sticks out to me on the galaxy the Sigma clearly had a advantage and you were able to discern a fairly signifigant change in S meter. Hooking up your Kenwood trying to notice the same difference with a bar graph meter now all of a sudden that advantage went away.

Well, that wasn't what I saw even though I no doubt made at least one error in seeing Russell's signal at an 8 on the paper report for the S4 when it should have probably been a 9. This one event happened starting at 3:17 minutes. Maybe I missed it and recorded another instance which was different.

At the very best and considering there were no more errors made on my Signal Report #27 dated 2/3/11, then the GM would still show a 6.8 average while the S4 improved up to 6.6 average, so the GM still shows a little better. That said, I think you're probably right, with the TS570 the signal advantage was not quite as obvious and maybe disappeared, but we still have to consider the AGC affect and with the bar type indicator we can't see as much, so maybe even with signals at a further distance showing less signal we might not see a similar result.

My point in all of this extra detail effort was to show ya'll how really close I've been seeing this stuff for years and saying the same repeatedly, realizing all the time that most didn't believe it, and maybe they still don't.

 

[MrSuburban]

Were you poking a finger in 007's eye with the reference to phasing where you were trying to be factious? Shame on ya'.



Well, that wasn't what I saw even though I no doubt made at least one error in seeing Russell's signal at an 8 on the paper report for the S4 when it should have probably been a 9. This one event happened starting at 3:17 minutes. Maybe I missed it and recorded another instance which was different.

At the very best and considering there were no more errors made on my Signal Report #27 dated 2/3/11, then the GM would still show a 6.8 average while the S4 improved up to 6.6 average, so the GM still shows a little better. That said, I think you're probably right, with the TS570 the signal advantage was not quite as obvious and maybe disappeared, but we still have to consider the AGC affect and with the bar type indicator we can't see as much, so maybe even with signals at a further distance showing less signal we might not see a similar result.

My point in all of this extra detail effort was to show ya'll how really close I've been seeing this stuff for years and saying the same repeatedly, realizing all the time that most didn't believe it, and maybe they still don't.

So your saying in the test with the galaxy the Gain master did better? I think you need to watch your video again, clearly the Sigma at least thats what you were reporting as the antenna definatly saw a higher signal by 1-2 s Units. When u did second test with Kenwood radio you now report the gain master as seeing better signals with bar graph meter and using tenths of s units again. You made solid progress with the first video.

Any difference in signal strength you will see is going to be when station is further away in close signal you are not taking advantage of the antenna and i am afraid to say a 1/4 wave GP will probably show same signal, but when you are going down the road the Sigma from what I saw in your video clearly had a better signal with out question.

 

[Shockwave]

To see the advantages with the Sigma design requires you examine your fringe coverage area for improvements. The low TOA and compressed beamwidth are not always apparent at the S-8 signal level. When dealing with the fringe coverage area in the FM mode, this antenna often makes the difference between a ear full of white noise and a signal that is pleasant to copy.

 

[Marconi]

So your saying in the test with the galaxy the Gain master did better? I think you need to watch your video again, clearly the Sigma at least thats what you were reporting as the antenna definatly saw a higher signal by 1-2 s Units. When u did second test with Kenwood radio you now report the gain master as seeing better signals with bar graph meter and using tenths of s units again. You made solid progress with the first video.

Any difference in signal strength you will see is going to be when station is further away in close signal you are not taking advantage of the antenna and i am afraid to say a 1/4 wave GP will probably show same signal, but when you are going down the road the Sigma from what I saw in your video clearly had a better signal with out question.

No, that is not what I intended to say, if I said it. I could be wrong though. Where I made a mistake was saying anything about Russell's signal where I was using the TS570 and noted the obvious error on my hand written Signal Report, but I didn't change it after the fact.

There were two videos, and the one where the lessor signal was going on was using the Galaxy and the S4 did definetely show a better signal in that video no doubt.

I don't think you were corn'fused and I would like to think I wasn't either...for sure on such an important Earth shattering issue.

 

[bob85]

eddie,
i enjoyed watching the sigma vs gm vids, thanks for taking the time to show us just what you are seeing in texas,

i would have to say on the galaxy meter the sigma4 beat the gain-master,
on the 570's internal antenna switch each antenna was ahead some of the time,
i see what you mean about conditions changing, you are stuck between a rock and a hard place, the fastest antenna guy can't swap antennas on the same mast fast enough for the conditions at your location,

larry and russle sound to have multipath phase cancellation / flanger effects,
i would not consider them suitable for antenna tests at the moment

 

[MrSuburban]

eddie,
i enjoyed watching the sigma vs gm vids, thanks for taking the time to show us just what you are seeing in texas,

i would have to say on the galaxy meter the sigma4 beat the gain-master,
on the 570's internal antenna switch each antenna was ahead some of the time,
i see what you mean about conditions changing, you are stuck between a rock and a hard place, the fastest antenna guy can't swap antennas on the same mast fast enough for the conditions at your location,

larry and russle sound to have multipath phase cancellation / flanger effects,
i would not consider them suitable for antenna tests at the moment

Bob do you have any locals say within 20-30 miles away you talk to on a regular basis?


Does there signal change to you everyday or at different times of the day if they don't change anything on there system??

 

[bob85]

i have plenty of locals to use for signal checks,
usually the signals are rock steady but lately we have strange conditions where occasionally we get multipath effects like fluttering signals, most of the time signals are stable, if anybodys signal is up or down somebody notices.

 

[Marconi]

Here is the beacon test on the Sigma4 vs. Gain Master

I don't think this is a duplicate test, but my intentions were to test on the beacon which is showing a lessor signal today and do it using the TS 570D and the Galaxy 2547 to see if there is a notable difference with the meters. I messed up though and had the 570 set on pre-amp.

Here are the two YouTube videos. If you would like to see a closer-up view then just click on the YouTube icon on each video and it will take you to a YouTube window.

Video #1
YouTube - Marconi comparing the Sigma4 vs. Gain Master using beacon #1

Video #2
YouTube - Marconi comparing the Sigma4 vs. Gain Master using beacon #2