!♡♡♡ it was fun looking inside this thing with you :) and at a fabulous price! Appreciate it hamFam

20 or so years ago I ran an almost identical MFJ-945E mobile on 11 meters, I used an RCI 2950 into an Elite Line TX2250 (about 200 watts) into the 945E Tuner and the antenna was a 102 inch whip on a pickup. Tuned fine from 26 to 28 Mhz and never any arcing inside.

741 always comes through ! Bought a 945E first video that came up ! Thanks Rob for the quick video ! That mystery hole port may have been for an off board RF sampler ? Seems to be a hole for BNC... 73 WA2KGG

My guess for the blue wire might be that it is a point to attach a scope probe through the hole in the back to be able to monitor your signal on an oscilloscope.

I like MFJ products. Back when I was into SWL I had an antenna tuner and preselector.

Very interesting tuner... Not bad for the price!

One word of caution. This is a T network and there is more than one setting that will give a 1:1 or low SWR. I think you want to tune for the minimum SWR corresponding to the highest value of the output capacitor. The previous owner may not have known that. I prefer L networks as there is only one combination of two controls that give you a 1:1 SWR. The coil is in series and if working into an impedance greater than 50 the capacitor is at the antenna end of the coil, but when working into less than 50 ohms the capacitor is on the transmitter side. Simply swapping the input and output cables is used on some L network tuners without an extra switch.

Good stuff Rob, like a detective

Video length

If you have a high impedance feed point the antenna the tuner will act as a voltage transformer to a

That’s a common place for arc over from running to Much power. I’d say probably had a 10:1 on 80 with mismatched coax length and it arced over. Adding that long screw would not help though ? Might want to remove that screw.

Previous owner was doing some Doc Brown Flux Capacitor mods !

$20 is a decent deal considering the tuner seems to function as it should. Too bad it had been butchered up. Sometimes these tuners can arc if the wrong inductor setting is selected and they throw high power to it. Some say that you are supposed to set the transmitter and antenna to zero and adjust the inductance for lowest SWR first, then fine tune the antenna and transmitter controls for lowest SWR. I have the MFJ-945E and have never had an arcing problem at 100 watts using this system of tuning. These little tuners are great to have around!

possible the hole held a micro toggle switch to put the tuner in by pass...i did this with my tuner

Nice find.

thanks, Another fantastic video 73 from kb2uew

From 80-10m it's a fine working little compact tuner. But absolutely not usable for 160m.without giving it a modification first.

Hi Rob,

Are you hearing anything about quality problems with MFJ tuners?

I remember you showing it to me when you bought it. I'll speculate that the mod was done to tune for 60 meters? I say that because 60 meters wasn't around yet when it was made.