[AMRadio] Kenwood TS-440S tuning knob binding

[Larry Szendrei]

Two weeks ago I posted the query (below) on these lists asking for 
suggestions on how to solve a stuck tuning (VFO encoder) shaft on a 
TS-440S. I have solved the issue, so am posting a summary in hopes that 
someone may find it helpful, either now or in the future.

Clif Holland on the Kenwood list (www.avvid.com/) suggested I first 
attempt lubrication between the shaft and bushing. Unfortunately I had 
no luck with this; in my case the shaft was bound up hard and beyond 
this treatment.

I ended up buying a VFO encoder on a popular auction site with 4 letters 
;-) at reasonable cost, which had been removed from a parts radio. The 
VFO encoder is buried pretty deep into the front panel of the rig, and a 
fair amount of disassembly was required to get to it, including removal 
of the 2 control boards (the board which contains the memory battery and 
the one directly below it). I removed the battery before removing the 
boards, as Clif warned me of the opportunity for shorting unknown points 
together when the boards are loose, and there are plenty such 
opportunities! I did not remove the boards completely from the radio, 
and only disconnected enough of all the cables to them to get them out 
of the way sufficiently to replace the VFO encoder, which is beneath the 
2nd board. There is a 3rd board beneath the 2nd one, but that one 
doesn't need to be removed, as it has a cut-out around the VFO encoder. 
The plastic front panel also needs to be removed in order to get a deep 
socket wrench around the nut on the VFO encoder bushing. After the 
boards were safely screwed down again and reconnected to the cables, the 
memory battery was reinstalled. I lubricated the shaft/bushing on the 
"new" encoder with 2 small drops of 3-in-1 oil before replacing the VFO 
knob, which, by the way, requires a 1.5mm Allen wrench for the set 
screw. A few more things - whenever working inside the radio I was 
wearing a wrist strap tied to the front panel metal frame, and I had the 
whole radio on a piece of heavy-duty aluminum foil, to avoid damage from 
ESD. I also used a grounded soldering iron to remove and replace the 
battery. Finally, Clif advised taking multiple photos during the various 
stages of disassembly, and I had to refer to one of them to make sure I 
got a pair cable connectors  back into their proper sockets on the board.

After I got it all back together (surprisingly enough!) the rig worked 
flawlessly. I am grateful to both Clif and my friend Mark KA2QFX for the 
helpful information and encouragement along the way.

73,
-Larry/NE1S

On 6/10/18 9:53 AM, Larry Szendrei wrote:
> I have a Kenwood TS-440S which I bought brand new in the mid 1980s, 
> which I have done my best to keep in pristine physical condition.
>
> This morning I was repeatedly manually scanning up and down the band* 
> with the VFO knob, and it quite rapidly started to turn harder and 
> harder. Now it almost takes a wrench to turn it.
>
> Anyone run into this before, and know how to fix it?
>
> Also, what type of wrench is needed to remove the setscrew for the VFO 
> knob?
>
> * I was playing around giving out a few points in the June VHF 
> contest, using the 440 in conjunction with the Hallicrafters HA-6 and 
> HA-2 transverters.
>
> 73 and TNX,
> -Larry/NE1S
>
>
>