#86 Fixing an Amateur Radio RF-Wattmeter

[@mikesradiorepair]

Nice to get a easy repair once in a while. Nice to see a good old meter ready to go back into service. Well done. Mike

[@TRXLab]

+MikesRadioRepair Hi Mike, yes you are right sometimes it is nice to have an easy one :-) 73

[@berndb.5097]

A very interesting voltage divider for the two scales. Two trimmer in series. I stored it in my lab notebook. Many thanks for the nice repair video.... 73 Bernd

[@TRXLab]

+Bernd B. Thanks Bernd, glad that you like it. 73

[@technos123]

Peter another nice repair. We live in a throw away society so Its good to see bits of equipment being fixed rather than just thrown into the dumpster.

[@TRXLab]

Hi, yeah you are right we are really living in a throw away society...Tine to do something.. Thanks for stopping by 73

[@WPF465B]

Good troubleshooting and repair, thanks.

[@TheRadioShop]

Very nice fix Peter. You are right, ham radio is more than making contacts.

[@TRXLab]

+The Radio Shop Hi Buddy, yes really it is :-) Thanks for stopping by my friend. 73

[@jlucasound]

I echo all the nice comments below. So great to get an older piece of equipment working 100% again. Thanks!! Your friend will be pleased. (Love the accent! I am guessing German, but I suppose you could be from the Netherlands.)

[@TRXLab]

Thanks for watching! Well the Dutch accent sound a bit different :^)

[@ninaevans4501]

Your reply does help and thanks. Rubidium would be a component of an industry standard product only, largely because it is a radioactive element. I cannot see any company letting a private individual have access to Rubidium (particularly with what is happening in the world at present). Thanks and warmest regards, Wayne and Nina.

[@TRXLab]

+Nina Evans Thanks and all the best 73

[@OrbiterElectronics]

Nice to see it fully functional again my friend. Cheers John

[@TRXLab]

+orbiter8 (John) Yes you are right John, nice to have it back in service. Thanks for stopping by my friend. Cheers

[@DonDegidio]

Peter, Nice repair and video. Don't you wish all repairs were as easy. Hi Hi 73

[@TRXLab]

+Donald D'Egidio LOL yes sometimes :^) Thanks for feed-back 73

[@dennisqwertyuiop]

As always great repair and video thank you Peter

[@TRXLab]

+DENNIS N Thank you Dennis! 73

[@Radiocruncher]

Nice easy fix for a change. Thanks for sharing it with us

[@TRXLab]

+Radiocruncher Hi, thanks for watching! All the best Cheers

[@DJCaverna]

very nice repair ... old POT have in all 80'' 90''CB RADIOS and after 20 years every pot is not on the perfect resistence or dirty... and need to re-adjust ...

[@TRXLab]

+DJ Caverna Haroldo Bradaschia Neto Hi Neto, thanks for comment. Yes you are right those old pots meed to be treated with care.. 73

[@cassvirgillo3395]

Hello TRXBench, Peter, I am new to Antique Radio restorations and may some day get into ham radio, funds permitting. Someone suggested your channel and said you were a good tech, I agree, and, I subscribed. I look forward to checking out a lot more videos and learning all I can from your obvious years of experience, Thankyou. Take care, C.

[@TRXLab]

Ah okay very good! Thanks for watching and subscribing. I'm glad that you have a need for my videos. 73

[@craigtucker777]

why not replace all 4 and recalibrate, little bit of kontakt61 on switch, nice meter, thanks for upload.

[@TRXLab]

Hi, you always have to take into account what the owner want you to do, so basically very simple. Thanks for watching 73

[@cesargabrielachar344]

Hola !!! Podrás subir el circuito eléctrico del wattimetro?? Saludos

[@stony7827]

thanks for this video - looks like an early Götting model.

[@johngulliver6151]

Thanks for posting Peter well explained

[@TRXLab]

+John Gulliver Hi John, thanks for comment and watching 73

[@jamessawyer4625]

Nice fix It looked like the meter is not adjusted to zero which sets the meter low reading. it works as well as it is designed for. good job

[@robertcalkjr.8325]

Good job Peter, thanks.

[@TRXLab]

+Robert Calk Jr. Thanks for stopping by Robert. All the best 73

[@NewHamInTown]

Thanks for an excellent and informative video.

[@TRXLab]

+NewHamInTown No problem, you are welcome. Thanks for comment. 73

[@PapasDino]

Nice fix Peter. I wonder if a drop of DeOxit on the old pot would have cleared the corrosion or was there in fact a mechanical fault? Those old exposed ring pots are notoriously bad but don't usually fail outright. But seeing the lucky SMD pot refit though was worthwhile! Keep sharing the great videos! 73 - Dino KL0S

[@TKomoski]

Dino I think it was a bent wiper, because when he pressed the wiper the pot conducted. If the resist was dirty pushing on the pot would have not made a difference.

[@PapasDino]

+T Komoski You're probably correct; my initial thought was when Peter pushed on the edge of the pot that it might actually be a bad solder joint underneath the pressure point. Interesting to see if Peter tested the "bad" pot after and if it actually revived what a little bit of DeOxit may have done for it. Thanks for the observation!

[@TKomoski]

I'm just surprised he didn't replace all four pots because he had a package of four.

[@TRXLab]

+T Komoski Yes you are completely right mechanical!

[@TRXLab]

+T Komoski all other were just fine put some DeOixt on and no problem :-)

[@ninaevans4501]

Another fascinating video. By the way, I notice that you have a box in the background on your bench. It has Atomic Rubidium Standard written on it. This is interesting. Could you please tell me what it is used for, and at some point, could you show how you could build such a device? Warmest regards, Wayne and Nina.

[@TRXLab]

+Nina Evans Thanks for feed-back Nina. The Rubidium is my frequency standard in the lab for calibrating all my OCXO's frequency sources against to work with highest possible accuracy. A standard like this can't be build in a lab like mine. Therefore you need industry standards... What you see is a housing only. The rubidium is an industry product. Hope that helps 73

[@gregorywest2029]

Nice job, Peter

[@TRXLab]

+Gregory West Again thank you Greg

[@TKomoski]

Good morning from Vancouver, Canada. Peter why would the zero level be off when switching from 2kw to 200w. When the meter was set to 200w the zero level was below the line compared to 2kw it was spot on. Is that just meter panel itself at low range to cause that. Love the Signal Hound SA44B great little unit, mines older so I'm going to send it to signal hound for firmware updating and calibration. They are really good at answering your comments and questions. Great video's keep them coming, Cheers.

[@TRXLab]

+T Komoski Good Morning :-) Yeah I have seen it on the video when I was editing it. It must have been a parallax error through the lens somehow. It is not there in reality . Thanks for watching and have a nice day!

[@3ewinning3e82]

Sir, do you know what value "uH" are those rf chokes in that amateur wattmeter ? and the other answer, the vk200 2 1/2 turns what value uH are? I've a diy inductometer and say 4.7 uH for vk200 :/

[@TRXLab]

+3E WINNING 3E Hi, no sorry I didn't take the values.. 73

[@hans429]

A: and here nice the root of our problem.. B: lies? A: nice!!!!!

[@Rajeshkannabusinesswith]

Schematic circuit diagram please

[@herbertsusmann986]

I had very similar problem on my meter. I was able to DeOxit but yours seemed a little worse. Nice fix! If it was me I would have replaced all 4 pots maybe?? or at minimum spray all pots??

[@TRXLab]

+Herbert Susmann Hi Herbert, it was a mechanical issue but no need to replace all as after some cleaning with DeOxit they are just fine. Thanks for watching.

[@MrChrobi1]

Goog job!

[@grantfullen9559]

Nice Job Peter :)

[@TRXLab]

+Grant Fullen Thanks Grant! 73

[@brianwoodard233]

thanks BOSS YOU R THE MAN!

[@TRXLab]

LOL Thank you Brian..73

[@johnwest7993]

I waited 14 minutes to see if it was the pot or the switch, knowing it was either 1 or the other. I'd take the time to replace all 4 pots because the others look just as corroded and will soon cause more problems. I should really go build something, but I'm lazy. It's so much easier to watch someone else work. :)

[@alancordwell9759]

No surprise there Peter! That style of pot is famous for it :/

[@TRXLab]

+Alan Cordwell Hello Alan, yes that is true...very famous for that :-) Thanks for stopping by. Cheers

[@bundylovess]

Nice job

[@TRXLab]

+allan mitchell Thank you Allan! 73

[@cesargabrielachar344]

Alguna persona tendrá este circuito del wattimetro??

[@jeromegrzelak8236]

I AM INSPIRED

[@TRXLab]

Thanks for watching 73

[@владимирворонков-й9м]

please show the diagram of the device . I wanted to repeat it. привет из России.

[@StreuB1]

Great video, thank you! N0BPS

[@TRXLab]

+Brian Streufert Hi Brian, thanks for watching and comment 73

[@владимирворонков-й9м]

Питер дайте ссылку на схему с уважением Владимир UD3SBP. 73!

[@TRXLab]

sorry those units do not support a diagram...

[@1112223333111]

I knew it, ham radio has a pot problem. lol ;)

[@TRXLab]

+ᗒ╬ᗕ1112223333111ᗒ╬ᗕ LOL yes obviously :^) 73

[@joopterwijn]

First zero the meter :-)

[@TRXLab]

+Joop Terwijn Hi Joop, yes first mechanical and then electrical.. Thanks for watching Cheers

[@cranegantry868]

Replace all 4 pots (they are oxidized) AFTER you measure the setting they are on. Do not adjust them, that is pointless.