[Premium-Rx] COLLINS 51S-1 RF ALIGNMENT QUESTION

[pat1mca at aol.com]

Greetings to All,

At the moment I have a 1969 R/E Collins 51S-1 in for repair/alignment and a 1963 manual, but there are confusing differences discovered between the two concerning the RF section alignment.

There are many very knowledgeable 51S-1 owners who might know the answer to this, so here goes.....

On Page 4-5  Section 4.4.6  R-F Alignment in paragraph c. it states: "Set the main tuning slugs, L32, L68 and L72 to 5/16 inch less than full insertion into the coils"

OK. So does this mean 5/16 inch from the top of the slug down to the top of the chassis as a reference OR is it 5/16 inch up to the coil slug in the coil former using the open end of the coil former as a reference below the chassis ?

A later version 1975 Rev 11 manual is on order from the USA but in the meantime this is intriguing me. It is obvious that a previous owner has played around with the RF side and I need to start from basics again. The last time I worked on one of these fine receivers was over 30 years ago. I still consider them to be a "Premium Receiver", the extremely clever mechanical design is unsurpassed.

A definitive answer would be greatly appreciated.

Thanks

73 de Pat G3YFK