{Collins} Preselector slipping on 75S-1

["Ken, WA2LBI" <wa2lbi@xxxxxxxxxxxxxxx>]

Good afternoon, 

I am new to the reflector and recently joined because I received a 75S-1, 
32S-1, and SM-3 from a friend who wants me to put them back in working 
order. The equipment hasn't been used for many years but was stored well. 
Everything is clean and in very good physical condition. However, since I 
don't own any Collins gear (yet!) I am not familiar with the mechanicals. 

I need help from one of the "preselector gurus". My problem with the 75S-1 
is that preselector is slipping. I can move the tuning rack up/down by hand 
but the panel knob, although I feel some resistance, just spins. I noted 
that if I pull slightly outward on the knob while turning it does move the 
rack up/down. I need to know how the preselector mechanism works and what to 
look for. I also need to know what NOT to do! What about lubrication? 

Any and all help will be appreciated. 

Thanks, 

Ken, WA2LBI 

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