Tuesday, March 1, 2016

Repair MFJ948 deluxe versatuner II

I actually bought this tuner new around the year 2000. It costs a small fortune at that time. I sold it to PD0FF when I bought the Palstar AT1KM. Now, years later I sold PD0FF's equipment for him. Only this tuner had a burned switch, I could not sell it and bought it back from him. Buying a new switch from MFJ is too expensive.

Original MFJ switch
And I don't like this "new" MFJ switch at all as it isn't a ceramic one as the original one is. At Classic International I found one that has to cost 46,75 euro (inc.shipping and VAT). That's more then half the complete tuner is worth. I did consider a variable inductor, but that is too expensive as well. So the only option was to get one on a radio flea market.

In a pile of components I finally found a very nice 12-pole switch with 2 decks. It isn't ceramic but you can divide any high currents over the 2 switches. So, thats what I did. Soldered in the new switch, which wasn't easy. But it seems to work fine. Tested out with 100W and it didn't blew up ;-). I expect it can hold 300W max. again. I'm lucky to still have the manual by the way. Have been searching on the internet but the manual for this old 948 model is hard to find. The new model manuals hasn't got any electrical diagram in it anymore

PD0FF's PL259antenna connectors seems to be not too tidy and you could call the PL female chassis a bit dirty. Luckely my wife sells some great cleaning stuff. And I can use it for free ;-). It's environmentally friendly and one of these is blue multipaste. Together with a special cloth you can clean everything from chrome, glass, tiles, stainless steel and many more. The nice thing with this is you don't have to use any force to clean it. Just rub it with the paste on the cloth and everything shines as new. Oh, by the way, in case you wonder, of course this is some advertisement for my wifes business ;-)
Comparisation COAX 1 and 2

Repairs, repairs....our 2 year old Samsung washing machine went crazy. A close inspection reveals that the dampening rubbers from the motor are completely gone. Click on the photo to see details. Only some black dirt was left at the bottom of the machine. The red arrows show were the rubbers should be. I think this shouldn't happen after just 2 years? A quick survey on the internet gave us the info that many Samsung users have this problem and repair is costing almost half a new machine. Being in the repair business I learned to think out of the box sometimes. I made a quick solution from PVC tube wrapped with selfamalgating rubber tape. It fitted just fine and the washing machine is turning the laundry nice and easy agian.


  1. Heb hier op zolder ook nog zo'n mfj948 staan. Werkt goed maar heb liever mijn Smatch.
    Mooi dat je de wasmachine kon repareren. Dat zijn van die dingen wat niet stuk moet gaan..

    1. Hallo Peter, ja een S-match is veel beter. Wil ik ook nog een keer bouwen. Maar deze had ik nog en het is zonde om het weg te gooien.

      Wat betreft de wasmachine, dat is een belangrijk ding. Zonder wasmachine geen huishouden. 73, Bas

  2. Good evening Bas, very nice repairs all the way around! As for the tuner nice job on hunting down a reasonable switch. With regards to the washer I too have had major appliances that gave me problems only after a short time of having them. It for sure would seem Samsung would know of this issue but has the nerve to charge 1/2 the price of a new machine to repair it. Excellent that you were able to repair the motor mounts.
    73, Mike

    1. Hello Mike, forgot to mention I bought the double deck switch for only 1 euro !. Yes, I'm glad I could save the washer. 73, Bas


Thanks for your comment. Bedankt voor je reactie. 73, Bas