S Meter Reading after Service

Brian Denley KB1VBF

How many spectrum analyzer receivers have you owned?  Those older receivers, as was said before, were just looking at the voltage coming of the AGC circuit.  Elecraft went though this same argument with their K3 owners and eventually provided two different outputs to pacify some.  SDR console went through a huge fight even after Rob Sherwood told them why.  Flex has gone through this before.  I’m not saying that there’s nothing wrong with your radio but understand that these receivers also measure whatever noise their own circuits pick up.  One way you might check:  take your radio to another location just to see if you get the same results.
Brian KB1VF

Burt Fisher

When I go the supermarket and go to the delicatessen they don;t start the scale at 7 ounces to account for the weight of the container, they zero it so you only pay for the meat. The reason zero is important no one cares what the electrons are doing inside the rig, users care what is coming in from the outside. The value of my Flex is maintained of Flex does well, this idealtic superior attitude does not go over well in the marketplace. When the Elecraft K4 comes out and Flex does well, I was wrong. I don't want Flex to ne a niche transceiver. They set the pace in SDR technology, after what other receiver can capture so much of the high frequency spectrum? The product (currently) is superior but the arrogance on this S-meter issue doesn't help. Are Kenwood, Icom, Elecraft, Yaesu all wrong in the way they present the S-meter?
A simple yes or no will suffice.  

Burt Fisher

N2WQ, you are right, that is the way it SHOULD work.

Burt Fisher

Whatever side you are on, on the S-meter issue I like your meter.

Michael N3LI

I want the S-meter to reflect the values as in the image. That is all.

Some people want accuracy, some people, for some reason I cannot fathom, demand inaccuracy. If the best reason is "because that's how it used to be done, even if it's wrong, well - that dog doesn't hunt. Might as well ask for phase distortion to be put back into Flex radios, or demand putting old USB to Serial adapters and Stero cables to run the sound from the radio to the computer because that's how it was done since 1999.

I'm not really certain that my wish for an accurate meter is arrogance. I want my ALC, power levels, S-Meter SWR meter to be accurate.

All of this is because Flex has exposed a dirty secret of Amateur Radios, and some want the inaacuracy to stay secret. The world is changing, and I really suspect that modern Hams prefer accuracy to inaccuracy. 

Brian Denley KB1VBF

Burt:
As far as I know, they match Elecraft and the Anan radios (both of whom went through these pains) but Rob Sherwood would be the definitive source here.

In any case, there might Very well be something wrong with his radio but we have suggested some things to try to prove that one way or another.

Brian KB1VBF

KY6LA_Howard

Wow.  An ICOM S Meter for those who want mythical readings. 

Brian Denley KB1VBF

Burt is incorrect in putting Elecraft in that pile.  They fought the same battle.

KY6LA_Howard

Depends on the Ground Quality  and FREQUENCY and Ambient noise he picks up from his power supply and common mode currents. 

Brian Denley KB1VBF

 http://elecraft.365791.n2.nabble.com/K3-S-meter-td1120138.html

Just a sample from the Elecraft reflector many years ago...

Stan VA7NF

Here we go again - Same old, same old.
It occurred to me that vintage radios (Japanese circa last year) inject a DC voltage into their AGC (they call the knob RF Gain).
As you turn down the RF Gain the S-Meter rises, well into the S-9+20db range; if I ground the antenna when the RF Gain is turned down the meter still reads S-9+20, not zero. 
Instead of the RF Gain, Flex uses the PreAmp, only they maintain +/- 0.5 dbm accuracy at all levels but only when the source signal exceeds the minimum A2D threshold.
We have many English words that cover many posts on this thread including "Dumb" and it's many synonyms or in modern lingo "Troll" 
G'Night all.

DJ1WT

We all know noisy receiver (e.g. JRC some years ago) masking weak signals, perhaps this Flex is one of those?

Michael N3LI

It's quite possible. Unfortunately some of the troubleshooting might have been askew, leading to the never-ending Flex S-Meter versus legacy meter discussions.

Michael N3LI

Well now, that  was interesting reading.

I can check out our K3S to see if it reads similarly. If so, I'm suspecting the new K4 will also have an accurate meter, which will disappoint some folks. 

Mike VE3CKO

Everyone is entitled to their opinion and when presented with facts, not fiction, you would think it would be better to take off the blinders and be acceptable to new information, new possibilities. If you own a Flexradio you are on a voyage to new frontiers and to go where man (ufacturer) has gone before.
Some people fear change, legacy is what they know and understand and that is all ok. Loyalties to your favourite radio (yes, that;s the Canadian spelling), is ok too. But me thinks it crosses the line of common sense when loyalties or stubbornness lead to spreading fake news. So glad we have so many tremendously knowledgeable folks here to set the record straight.

John KB4DU

Joseph;

I've been testing my 6400 based on your concern. Can you try an experiment to see how your radio compares to mine?

1. Click on the S-meter reading to change the scale to dBm.
2. Select RX A on the ANT slide out.
3. Set the RF Gain to the very left on the ANT slide out.
4. Set the Mode to CW.
5. Set the Bandwidth to 500.
6. Set all the DSP items to OFF.
7. Select a Frequency on 80M, 40M, and 20M and record the dBm reading for each one.
8. Post it on here so I can look at it.

Thanks

KY6LA_Howard

I guess it’s Time to Repost this very informative graph which clearly demonstrates what you can and cannot hear.  It’s really sad that the Trolls keep on crawling out of their caves to pollute this reflector with fake news.   

AC9S

This graph is even better with the various S meter levels indicated on the vertical axis.  I keep a paper copy in my desk for the occasional question about my quiet band S meter readings.

Keith - AC9S

KY6LA_Howard

Brian Denley KB1VBF

Great point!  Joseph: do you still have the Perseus?  It has one of the most accurate s-meters on the planet, if I remember Rob Sherwood’s ratings.  We could get to the bottom of this quick!

Brian Denley KB1VBF

After all this, if Joseph still has that Perseus, this issue will be resolved.  Rob Sherwood rated that radios s-meter as one of the most accurate.

Rolf Auras

John,

this should be done by several users. So we can compare the results and see certain irregularities, perhaps.

And we are NOT talking of atmospheric noise or man made noise (see graphs below) coming in via the antenna port (which should be terminated in this test), we are talking of noise only which causes the S-meter to go up to e.g. S6 and can be listened in the phones; and which source is unknown at present.

By the way, the Elecrafts did not show such a behavior. The reflector clips (s.a.) do not deal with this problem.

Joseph Rodick

I have always considered a signal report to be just that.  A measurement of their incoming signal.  If on 80/40 If I am getting an S5-S6 on a short input, then do I give that person a S5-S6 plus any increase or do I give them just the increase?  Honesty is giving a true signal report.  Yes every receiver and antenna system will receive differently and time/day conditions play a lot into it, however, at the end of the day, a signal report is just a measurement of how strong they are coming in at that moment in time.   If my noise level is an S whatever then I would give them a signal report of noise level + their signal.  However, If I am getting an S5-S6 with a short input, then what?  

Joseph Rodick

Both the Icom 7300 and the 756 pro III showed no S reading hooked up to my same PWR and Antenna System.  Like many, I am just trying to understand.  Thank you for your input.

Joseph Rodick

Mike thank you for your input, I used to teach electronics for Sears and STAC and have been retired for 5 years.   I just, however, can by the life of me understand how a short RF input can show an S5-S6 other than it being an internal noise level.   I must have taught a lot of people wrong, I used to teach them to short out the input to zero it.  wow, if that's the case I feel really bad.

Joseph Rodick

John thank you for your input, however, I lost friendship with two individuals that came over to compare my flex to their Elecraft and Icom.   Both were upset that the flex far outperformed their radio.  Even though I tried to make them feel good about their radio, it was apparent that they were upset.  Sad, one was a 40-year friendship.

Joseph Rodick

I had to sell the Perseus to raise money to buy the Flex 6400M.  I have found Flex to be the most honest, caring company I have had the pleasure to deal with from my first purchase of their 3000.   I am starting to feel bad in two different ways.   I used to teach electronics, and in the past, I taught my students to short out the input to zero out the meter or scope and because I my ignorance I may have taught them wrong and have caused this issue to prevail in this community.  Thank you for your input and God Bless.

Pat N6PAT

Joseph,

have you tried moving your Flex to another location? Perhaps a friend's house a few miles away? That way you can eliminate the possibility of a noise source within your own home.

Pat N6PAT

Not much of a friendship if it can be ruined by a a simple ham radio.

Excuse me but something appears to be pulling my leg

Burt Fisher

https://youtu.be/B6B89jvjto8