S meter calibration. Is it 50uV or 100uV for S9, its both. What is dbm, dbu, uV and load.

[@zooyawk4526]

nice to see that you have the time to make these terrific Clips once again. Sharing the knowledge is what it's all about. thanks again Mike

[@andythrasher9288]

Beautiful! Right on the money! Which is why having come from the FM two-way service field, when I first started doing CB repair and alignment, the service manual would reference S-9 at 100uv, and when Id do what I thought was a beautiful professional alignment, the S meter would be pinging of the right side of the meter on receive, but calibrated just fine on the power output scale in transmit. Gave me fits until I figured it out. Also it should be noted to use 50 ohm test cables on the bench. Thanks Mike!

[@marklowe7431]

Awesome video. For all the reasons you mentioned.

[@ScientistPrepper]

This is great. Clear as mud. No just kidding. Great video, just real confusing with all the different units.

[@ElPasoTubeAmps]

Very good video. HP manuals try to explain EMF as the internal, and as you say, not loaded voltage, inside their instruments but it is not the voltage at the output terminal into a 50 ohm load. Yes, it can be confusing but I think you did a good job explaining it. Nice equipment you have. And I learned from you about the difference above 30 MHz. Got to keep it complicated or it wouldn't be fun... :-)

[@earnieb5318]

Mike, I've gotten used to "get ready" when you start video with "This is going to be a short video" I go and put a rack of ribs on grille and get mucho 🍺 to go along. Happy to say you didn't let me down!! Yep, you did similar.some time back but enjoyed my ribs and 🍺 just like the first time! EXCELLENT JOB again!

[@mikesradiorepair]

Earnie B I have so many to upload it's not funny. Figured I better stick some up today before people go through withdraw.

[@kenm0bqh163]

Mike I just came across your video due to purchasing and using a Sinad meter and I have found what you have spoke about on this video very useful. I love the 2 charts you have printed out for measurements above 30Mhz and measurements below 30Mhz, do you have a source link where i can print these off or an email address I could contact you on to send to me I would appreciate your response. Thanks again

[@mikesradiorepair]

www.giangrandi.org/electronics/radio/smeter.shtml

[@kenm0bqh163]

Thanks very much 😊👍

[@anthonyduffy2440]

This is great, just the information I needed. Thank you.

[@TheDefpom]

I tune to -67dBm myself, I got that from a service manual years ago, and stuck with it, maybe I should investigate that level! Strangely when switching measurements on my Marconi it say -67dBm for 100uV... now I have to look into this !

[@mikesradiorepair]

TheDefpom LOL, there's just to many ways to measure the same thing. I swear they try to make it confusing.

[@TheDefpom]

I just powered it up and yep, I wasn't imagining it... 99.9uV is -67dBm on it... BUT I notice it is "uV pd"... arghhh. I just did a conversion search... found this as my first result: wa8lmf.net/miscinfo/dBm-to-Microvolts.pdf

[@TheDefpom]

Every cross reference I'm finding is saying -67dBm is 100uV, WTF?

[@justinruth9729]

So what do u do mike on your bench????

[@ko4nrbs]

Could you show a S Meter calibration using a RF Generator that requires a Step Attenuator and RF Volt Meter to make sure of the output. Most of us don't have access to high end test equipment so have to make due with older equipment. So in order to inject a -73dbm or 50uv signal to achieve S9 we must improvise using what test equipment we have available. Great video by the way!! Thank you, Bill

[@DonDegidio]

Mike, You addressed the difference in EMF measurement with this video. 73 WB3BJU

[@mikesradiorepair]

Donald D'Egidio Have been getting questions from people asking why one manual said 50uv and the next said 100uv. Figured I should explain it a little better.

[@DonDegidio]

I didn't realize there was an EMF spec for S meter setting. Did a good job of explaining it. It should put the confusion to rest. 73 WB3BJU

[@cuban9splat]

VERY good explanation. This issue has confused many people for years (including myself). Thanks Mike. 73 de K7RMJ Frank

[@peternewman958]

Hi MIKE great explanation as usual, years ago before the internet I had the same question myself. I can say it took some time in libraries reading tech books to find the answer. As usual thanks for taking the time to post some more excellent videos. People may have started sending poison letters to you. Oh no they wouldn't people don't now how to write letters these days it's all txt or email..LOL

[@trombabaroque]

Thank you, Mike! Great explanation, giving answers to many questions. 73, Stefan/OE6ISP

[@chickenhawknwc]

Can you tell us what is some good equipment to use for cb repair and alignment, I have heard that the B&K was not that great What do you think of the Leader brand of test equipment?

[@mikesradiorepair]

+Hawk N.W.C. Nothing wrong with B&K equipment. They have been around for a long time and use to make CB specific equipment back in the day. I use a 1040 and 2040 almost daily and they both work flawlessly and we're both built in the 1970's. Only thing I have ever done is recap them (as would be expected for anything 40 years old) and annual calibration. I also have a lot of Leader equipment and nothing wrong with their stuff either. Also don't forget Sencore. Another company that made a lot of field specific test equipment. All three companies made equipment that was designed to be used in the field by techs.

[@injoelsgarage3934]

Mike, Great video. You are always so informative. Had completely no Idea! Can you make copies of your charts with your notes available to Us? Would help a lot of us out. Thank you so much for sharing. Blessings Joel

[@mikesradiorepair]

+In Joel's Garage Just do a Google search for dbm to uv conversion chart. You will find several pages of different charts. That's where I got these.

[@injoelsgarage3934]

Thank you Mike. I will yet today.

[@bradcfi2]

Nice Job!

[@williamcolvin3609]

What if all you have is an old Heath-kit IG-102 SIGNAL GENERATOR - that has no meter to see the voltage output?

[@mikesradiorepair]

William Colvin Then you need some way of measuring signal level. If you plan on servicing transceivers you should probably get a more modern RF generator. The old Heathkit is fine for tuning up AM receivers and working on TV's but to work on transceivers you need to be able to provide calibrated outputs at less than 1uV. Also, that generators frequency isn't really going to be stable enough to perform work on SSB receivers where the slightest frequency change makes a noticeable difference.

[@williamcolvin3609]

There is no repair shops anywhere near where I live,and the ones that I have heard of are chop shops and I have repaired some of their damage. I only have a basic electronics knowledge from the first part of an Instrumentation Course and an Industrial Maintenance Course and have built DIY Kits,but Radio Electronics is a whole new ballgame. I am disabled and on very limited income and trying to help others in my area to enjoy the CB Hobby and pass our spare time. Is there anything from China or anything reasonable priced that I could use?

[@mikesradiorepair]

William Colvin In the upcoming course I am currently working on it will be covering things like this. Stay tuned is the best thing I can say. Ebay and other auction sites are a great resource for cheap used equipment. You can buy equipment that cost near or more than 100K for pennies on the dollar if you really search for the bargins.In the last 4 weeks I have gotten 3 high end communications test sets for less than 1K. The one I got yesterday only cost 350. The bargins are there for the taking.

[@williamcolvin3609]

I have had some severe head injuries and nervous breakdown and just looking at a Communication Test Set confuses me with all the features. Every time I find something on E-Bay that looks usable I get outbid on and everything else when I look someone else gets the deals before I get the funds to afford it. I have a Lafayette CB Tester,but cannot find any information for it.

[@williamcolvin3609]

S143795 Fluke 6061A Synthesized RF Signal Generator 10KHz - 1050MHz is this something like you were talking about,they have several units like this on E-Bay for parts or not working around $300.00 once you add shipping.

[@DonDegidio]

Mike, I seem to remember you addressed this in an earlier video? Still a very good video. :-) 73 WB3BJU

[@justinruth9729]

Mike I'm not here to argue but been into this for 27 yrs...I was thought that s-9 signal @50 ohms is -93dbm ....

[@mikesradiorepair]

It depends on what frequency you are talking about. It's -73dBm for signals below 30MHz and -93dBm for frequencies above 30MHz.

[@justinruth9729]

Now some use 1khz signal input at 60mv -100...input...but it depends on frequency sir..iny opinion once u get out of 30mhz ther is actually a proper set for each...this is how I was thought so ...this is we're i stand!!! For cb we were taught 60mv also some use dbm .... Modulated 30 percent ...some use 100 some use 50 .......????

[@NoName-mr1lh]

I've seen -80 dBm in my radio service manuals.

[@justinruth9729]

All this is load dependant

[@TRXLab]

yes that is very much confusing for young players :^)

[@ronedwards8239]

Fact is most of CB radios, black box radios don’t track at all! -85dbm should be 7 S units. I have seen 8.5 S units. Even compromising the S 9 setting at -73dbm. I worked in the precision instrument business for 16 years. Most S analogue meters used in CB and some ham radios cost 50 cents to manufacture. They will not track accurately and are absolute junk!

[@stevejoos8953]

Two pieces of constructive criticism that I hope you take with the spirit in which they are intended : 1) You are subconsciously FAR too repetitive. You "open" with: "This is just a SHORT video. But in reality, it is nearly TWENTY ONE minutes, - that is NOT short. You keep going over the SAME thing over, and over, and over again in the first third of the video. You do not need to keep repeating the same thing over and over again, - it really detracts from the video. 2) I don't mean to be personal here, but you really need to cut your right pinky fingernail, - that is just gross. It ends up being a focal point throughout the entire video, because you seemed to flash and advertise it in the beginning of the video, and then people end up looking at it, and looking for you to flash it again throughout the video (because they are already bored because you are stuck in "repetitive mode". Don't let your "body parts" be the focal point of your videos. If you feel the urge to do all of that "pointing" stuff, - do it with a neutral pointing device like a pencil, or better yet, a plastic "spudger" tool. 3) Don't "laugh and giggle" during your videos, - right off of the bat, that is open admission that the video is less than professional. Save that nervous laugh and giggle stuff for the kids/teenagers. Try not to take any of that too personal, - just try to apply it going forward and you will doing a lot more to forward your message, and your view count will go up.