Bristol

[KB2WIG]

Do  any of uses know the decimal equivalent, in inches, for numbered Bristol spline drivers? My ART-13 manual specifies say, No. 8 driver to remove nobs. I want to purchase a set, but all I can find on line have the .decimal measurements, not the numbering system... klc

[flintstone mop]

Hello
You can see Bristol wrench sets on e-pay for $20.00. I bought a nice Excelite Bristol wrench set with a nice handle from an electronic store in 1995 when I was doing some work for Howard Mills and the Collins radios and my own R390A. Just do a Google search for 'Bristol Wrench Set'

I noticed thay are all in decimal measurements.
I hope I helped

Fred

[KB2WIG]

Fred,
Thanks. I wanted to be sure that I purchased the ones I needed but all I have to go on is the Collins/Bristol driver number.The epay stores want $18 + shipping.....  maybee I find something at Rockchester....   klc

[w5rkl]

If you're going to do work on any Collins equipment whether it's a 75A, 75S, 32S or 30L series, a Bristol/Star wrench set is a MUST. Without them you can't even remove the knobs off the front panel.

On the 75A series, most of the front panel knobs require a star wrench size T-10. The 1 khz dial collar has 2 set screws that require a star wrench size T-5. The velvet tuning KNOB on the 75A4 also  requires a T-5 star wrench but you will need the long "L" shaped star wrench to loosen the set screws on the knob. Also the brass inner gear plate that rides on the PTO main tuning shaft, has 2 set screw each, both T-5 size. The gear shaft collar that the large knob on the velvet tuning shaft has 2 set screw and both are also are T-5.

A company called "Cresent" sells a star wrench set with small short size hex shanks that includes a long magnetic handle. This is available at Lowes Home and Garden for $17.00. I have not tried Home Depot so I do not know whether they sell them or not.

I was fortunate to find a nice IIT magnetic handle 30 piece set with a seperate T-5 through T-10 short size hex shank set that fits the magnetic handle at a local Bargin store for less than $10 complete with plastic and rubber carrying case.  This star wrench set will remove some knobs but the main tuning knob on a 75A series, you need the "L" shape Bristol wrench set that's sold on eBay.

The Bristol "L" shape wrench sets that are sold on eBay are worth the investment because they have the T-5 and T-10 star wrenches for the knobs and 1 KHZ round dial on the 75A series receivers. I can't say for sure whether they will fit the 75S, 32S or 30L series equipment or not.

When working with star set screws, pay close attention making sure the wrench is properly set in the set screw and that it's the right size. I've seen star set screws that were ruined because someone didn't have the right size and ended up rounding the inner part of the star set screw. Do not use an allen wrench. If you have to drill out a set screw, use a "Left hand" drill bit, not a normal drill bit and always use a variable speed drill, drilling in a couterclock wise direction (reverse). The left hand drill bits have been known to grip the set screw suffiently to loosening it so you can remove the screw. However, I can not guarantee this, each situation is different.

73's

Mike
W5RKL

[KB2WIG]

Mike,
Thanks.--- Lowes?!!    Just when you think you have things figured out..... I never would have guessed... I'll try them out after I finish here....  The leftie loosie drill bit trick was forgotten a long time ago.... again,thanks..        FYI   I'm losing the smoke out of (2) an/art-13's... one with a working autotune/one without and have decided to pull one apart.... I didnt want to butcher the fittings, so its off to get Bristol....    klc

[KB2WIG]

FYI            9 "key" set of wrenches  $13.95  + $2.00 shipping from MGS  in Georga....    dubya dubwa dubwe  dot  MGS4U