Yaesu Ft-101 E and F restore

Remember the front-end FET trick, and linque?

Yaesu loved the hell outta those things.

I love 'em so much that I ripped all of them out of the 901s and am in the process of converting their RF boards to use high-level mixing via an SBL-1.

Oh yeas, remember those!.


Well, Been a couple of weeks since I had a chance to even play with any of my projects. Over time is killing me plus all the repair work I have going on in the shop

When I last did both rigs were working with a few bugs.
Last night I fied up the E and was looking good. Then the RX fell to nothing. Very little hash in the speaker. :slap: So I said ok, I switched to the F aand fired it up. Good signals on 40 meters. Keyed the mic and no TX :sleep:

So a simple patch up job got the rigs going. But did not hold up. http://www.gokarters.com/vbforum/ima...lies/spank.gifSo both are going back on the bench for a full refurb.

Then just maybe all will be fine. http://www.gokarters.com/vbforum/images/smilies/sos.gif
I am going to Benson hamfest this Sunday. Hope to find some rare stuff. And see if I can sell off some other stuff.

Another ham I know is trying to fix an FT101, I think theres no letter at the end just a plain 101. He says :
"I have a problem with an FT101. It works fine on AM and USB transmit but on LSB it is transmitting +1.3KHz instead of -1.5KHz. The poor radio had been converted for use on 11 meters AM with an AM filter installed along with rewiring. It was done right but the customer wants it put back to original so I put it back and it still won't do LSB right."

He later informed me LSB and USB work backwards and the 3 mhz crystals are ok and theres 1 grey wire that was disconnected at both ends and he can't figure out where it goes. One end is somewhere around the mode switch the other is somewhere around pin 10-13 on the voltage regulator board connector.


Any ideas?

The grey wire went from the 11M driver circuit bandswitch position to a coil which was connected to ground. If you turned the bandswitch to 11M, RF power from the pre-driver transistor was shunted to ground. It was necessary to remove the wire if you wanted to use the 11M spot for, say, adding 12M.

Note that the connection and choke may not appear on the schematics for the RF section of the rig. I'd leave it disconnected and add 12M to the rig for your friend.

As far as the LSB issue is concerned: What do you measure for BFO frequencies when the rig is set to USL, LSB and AM?

Thanks, that explains the grey wire. He says the BFO frequencies on AM, LSB and USB are exactly right. 3181.5 for LSB, 3178.5 for USB and 3179.3 AM

Next thing I'd do is to take a look at those frequencies when in transmit. Also look at the VFO frequency - does it change in TX while set to LSB?

Ok turns out he was I guess testing it incorrectly , he says "it has to be tuned to upper sideband and lower sideband manually"
and I guess he forgot to do that. Thanks for the help.