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n2ize
12-07-2010, 12:02 PM
Okay, I dug a little deeper into my Yaesu FT470 today and found the part number for the VHF final that needs to be replaced. It's a Toshiba part and the Toshiba number is
M57796MA.

The good news is that it is still available. I found it listed in stock at "RF Parts". The price is not too bad either, $29.90, which is cheaper than many of the other solid state rf finals listed. Of course I'll shop around and see if anyone may have the part for less.

Of course if anyone out here happens to have this part laying around, perhaps a pull out from an old unit, etc. please let me know. I'll gladly compensate you.

The Bad news is that it's not going to be easy removing the old one and soldering in the new one. Real estate is very tight on the circuit board and there are one or two tiny surface mount components that are attached to at least one of the terminals that are going to have to be removed and probably replaced as part of this job. The hardest part is going to be desoldering and removing the old component. I'm going to need a very narrow soldering tip, a very steady hand, and a good vacuum or solder wick. If worst comes to worst and I don;t feel up to doing it myself, once I get the parts I may see if I can get hold of a local radio tech to perform the actual replacement. Otherwise I'll do it myself.

N8YX
12-07-2010, 12:05 PM
Check eBay.

I've seen a goodly assortment Toshiba modules listed there over the past couple weeks. Of course, the ones I need for a conversion project don't show up with any regularity...and RF Parts has 'em for $83/ea.

NQ6U
12-07-2010, 12:09 PM
Good luck dealing with the SMT stuff, John. I have to put on a pair of 4x magnifying glasses just to see a lot of those tiny components, let alone work on 'em!

I recently pulled the air pump out of a defective electronic blood pressure test unit; I'm hoping to put it together with an inexpensive soldering iron I have sitting around to create a home-brew hot air rework tool.

n2ize
12-07-2010, 12:20 PM
Check eBay.

I've seen a goodly assortment Toshiba modules listed there over the past couple weeks. Of course, the ones I need for a conversion project don't show up with any regularity...and RF Parts has 'em for $83/ea.

Thanks... Excellent suggestion. I didn't even think of trying Ebay. I'll see if they have it over there.

n2ize
12-07-2010, 12:54 PM
Good luck dealing with the SMT stuff, John. I have to put on a pair of 4x magnifying glasses just to see a lot of those tiny components, let alone work on 'em!


It's not easy for me to work on these things either. First I'm used to working on old stuff, chassis wired with tubes. You can work on those things with a crowbar and a welding torch. Also, nowadays I need magnifying glasses to work on these small components. 10-20 years ago I could work on them bare eyed.



I recently pulled the air pump out of a defective electronic blood pressure test unit; I'm hoping to put it together with an inexpensive soldering iron I have sitting around to create a home-brew hot air rework tool.

I think I have an old pump from such a unit laying around somewhere. Maybe I'll try building one for myself.