As a retired Failure Analysis engineer, I really liked seeing the inner windings of the inductor. I've analyzed many malfunctioning components over the years, including inductors, but this one was particularly interesting since I'm also a Ham. Thanks Peter! 73 de KZ9L
Glad I waited to the end , I was going to say , I like to take things apart to see failures - heatshrink off , and you did . For it's a learning opportunity - how things fail & sometime why they fail . ;) Thanks again
Hi Peter, good to see you back making videos, I am not sure that the current rating is the problem, more likely the reactance is not high enough. If you consider the RF voltage present at 1.5kW and the reactive impedance of those inductors at 1.8MHz it looks worrying... I may be wrong....
I was under the impression that MFJ made quality products, but other hams think different. I saw another video of yours where you took apart the bias tee and found wrong value inductors. I can understand that a person can have a bad day and grab the wrong part for insertion into a product. This makes the second MFJ bias tee to go wrong. I think I would have remembered the problem from a previous video. I don't think I'd ever buy a MFJ Bias Tee. So then 2ea. 47 microHenry would total nearly the 100 microHenrys that you need. I see on the little board that two can be soldered in series. W Rusty Lane K9POW in eastern Tennessee
Maybe it might have been a nearby lighting strike that caused the problem? Wonder if he had any lighting protection on the coax? Alway enjoy your videos and your method of troubleshooting. 73 wd4dda
I have MFJ automatic tuner and several of the diodes on the relays have been knocked off the PCB. It could only have happened at the factory. Says a lot about they quality control.
You can visually see the discoloration of the heatshrink on those inductors right around the middle where the windings are, it is clear they have been overheated.
danke, hatte schon "Entzugserscheinungen ". . . . . . hatte dieses Problem schon, was durch eine direkte Stromversorgung des MFJ behoben werden konnte. BIAS Tee bleibt für mich eine Notlösung. 73s
Very educational videos. I could mail you my Alinco DJ-V27T, 220 MHz HT, receiver is deaf. TX is OK. I bought it on ebay and discovered it could not receive, only noise. Tim W8RNG
Hi TRX man or anyone who can answer my question. Out of all the models of the Yaesu FT-1000MP which model is the best one ? Which one will prob work perfect and not have faults if I buy a used second hand one ? Thanks
I burnt out the choke in my T also by letting the thing see a low resistance somehow? only had one choke in the T, so I rewound the choke with the same size wire and back in service.
No, it has to do with the quality factor of the inductor (or "Q"). The L meter pulses the coil and then counts the number of "rings" of the decaying waveform. A high Q inductor will ring for a long time (larger number of rings or oscillations) compared to a low Q inductor. Shorted turns in an inductor will kill the Q of the inductor and will show a low number of rings or oscillations after an energizing pulse.
I was thinking the same thing...coil forms looked OK, but did he have any enameled coated wire of the same gauge? Probably easier to just replace the part.
insert a manual tuner betweeb auto tuner and dummy load -- and see if the auto tuner will compensate for the L or C you introduce. IMHO the MFJ is crap.
Hey Peter, Great to see you back and sounding so bright & chirpy. Excellent video again 👍.
Thanks
Good to see you back,
Thanks
Hallo Peter,
Es ist immer wieder eine Augenweide Deine Videos anzusehen.
Man kann so viel daraus mitnehmen.
Dankeschön!
As a retired Failure Analysis engineer, I really liked seeing the inner windings of the inductor. I've analyzed many malfunctioning components over the years, including inductors, but this one was particularly interesting since I'm also a Ham. Thanks Peter! 73 de KZ9L
Really enjoyed watching the fault finding and fix. Thanks
Glad I waited to the end , I was going to say , I like to take things apart to see failures - heatshrink off , and you did .
For it's a learning opportunity - how things fail & sometime why they fail . ;)
Thanks again
Excellent Job on the troubleshooting.... Love that LP-500 by the way. W1SWL
A nice way to start a Saturday after breakfast with the Hams.
Thanks for the video Peter.
THanks
Always interesting to watch your videos, Peter. Thank you.
Thanks
Hi Peter,
Those inductors were also the problem with my 998-RT. I replaced the two with one 100uH 1.5A inductor. Stay safe. 73 WJ3U
stay safe!
Great video really like that Sencore Capacitor Inductor Analyzer
Hi Peter, good to see you back making videos, I am not sure that the current rating is the problem, more likely the reactance is not high enough. If you consider the RF voltage present at 1.5kW and the reactive impedance of those inductors at 1.8MHz it looks worrying... I may be wrong....
Thank you Peter, always good to watch your video’s, very interesting 73’s
I was under the impression that MFJ made quality products, but other hams think different. I saw another video of yours where you took apart the bias tee and found wrong value inductors. I can understand that a person can have a bad day and grab the wrong part for insertion into a product. This makes the second MFJ bias tee to go wrong. I think I would have remembered the problem from a previous video. I don't think I'd ever buy a MFJ Bias Tee. So then 2ea. 47 microHenry would total nearly the 100 microHenrys that you need. I see on the little board that two can be soldered in series. W Rusty Lane K9POW in eastern Tennessee
Welcome Back! we missed you a lot!!!!!!! Danke !
Great to hear that
Welcome back Peter
I don't know if I learned something, but watching your repairs is good enough. *Cheers* *73*
as long it is enjoying you... take care
@@TRXLab Nice to see you working for the old man, maybe one day you can explain who the old man is.
Very informative and interesting. Good to see you back Peter. 73 de KB7ICI....Bill
Thank you Peter!!!
Another 'thumbs-up' video Peter, made my Saturday!
Thanks
Maybe it might have been a nearby lighting strike that caused the problem? Wonder if he had any lighting protection on the coax?
Alway enjoy your videos and your method of troubleshooting.
73
wd4dda
The MFJ's, economical as always, a fuse in the supply line would not have been bad :-)
true
Great video Peter. Thanks for creating this content. A lot of hams here say MFJ stands for something less desirable. 😀
good to see you back
thanks
Thanks Peter👍🏻🇬🇧
Thanks
Brilliant 😊
I have MFJ automatic tuner and several of the diodes on the relays have been knocked off the PCB. It could only have happened at the factory. Says a lot about they quality control.
Mighty Fine Junk
good work
Thanks
very well explained.... 😃
Seem to remember seeing you fix one of these bias Tees before?
Thanks peter for nice video, 73 de Pol ôn the island of Crete
Thanks
Nice video. Thanks!
Thanks
You can visually see the discoloration of the heatshrink on those inductors right around the middle where the windings are, it is clear they have been overheated.
so true...
danke, hatte schon "Entzugserscheinungen ". . . . . . hatte dieses Problem schon, was durch eine direkte Stromversorgung des MFJ behoben werden konnte. BIAS Tee bleibt für mich eine Notlösung. 73s
Dankeschön!
First!!!
Wish I had a VNA, just can't justify the expence at the moment.
Some day it will be possible
Very educational videos. I could mail you my Alinco DJ-V27T, 220 MHz HT, receiver is deaf. TX is OK. I bought it on ebay and discovered it could not receive, only noise. Tim W8RNG
Didn't you do this one in the past ?
But thanks for the video !
It looked familiar to me also.
Yes
@@TRXLab It's not a problem,, I go back over a lot of your videos for refreshing myself with a problem.
Thank You
Hi TRX man or anyone who can answer my question. Out of all the models of the Yaesu FT-1000MP which model is the best one ? Which one will prob work perfect and not have faults if I buy a used second hand one ? Thanks
I burnt out the choke in my T also by letting the thing see a low resistance somehow? only had one choke in the T, so I rewound the choke with the same size wire and back in service.
In this case the DC path is the issue.
does the ring value equate to the actual physical number of winds of the coil? if so, how does the tester actually calculate that value?
No, it has to do with the quality factor of the inductor (or "Q"). The L meter pulses the coil and then counts the number of "rings" of the decaying waveform. A high Q inductor will ring for a long time (larger number of rings or oscillations) compared to a low Q inductor. Shorted turns in an inductor will kill the Q of the inductor and will show a low number of rings or oscillations after an energizing pulse.
@@herbertsusmann986 very interesting, thank you
Good explained
Sometime the ringer test is the only way to identify a faulty coil, transformer, filter or what ever...
My question is: " Do you report this to MFJ?" or do you think the faulty part isn't meant for 1500W?
Hello Peter, was ther an option to recoil these 2 ?
I was thinking the same thing...coil forms looked OK, but did he have any enameled coated wire of the same gauge? Probably easier to just replace the part.
Yes it happens very often
MFJ - it's named Mighty fine junk for a reason. They are notorious for poor build quality.
I agree, but there aren't many options for radio gear anymore :(
Everybody I know agrees. Mighty fine junk. But again now many people make the things they do.
insert a manual tuner betweeb auto tuner and dummy load -- and see if the auto tuner will compensate for the L or C you introduce. IMHO the MFJ is crap.