mondo Posted December 29, 2019 Report Share Posted December 29, 2019 Hey guys, I've got a set of as-103as that I have been slowly repairing over time. I just received the replacement pots found on ebay (https://www.ebay.com/itm/AR-3-AR-3a-AR-2-AR-2ax-AR-4-AR-4x-AR-5-AR-6-wirewound-potentiometer-pot/163074984077?hash=item25f806c88d:g:mF0AAOSw4eJbEGaU). There is a major problem, though, which is that these "improved" pots are much larger in diameter than the originals. They will not fit in the holes provided on the metal back plate. The pots touch together and are too wide.. Any ideas? Should I drill out the hole? Get different replacement pots? What would you do? Quote Link to comment Share on other sites More sharing options...
Aadams Posted December 29, 2019 Report Share Posted December 29, 2019 Mondo I thought someone with 103s would have answered by now. If these pots are larger than lpads then they are large. Are you saying both stem and cylinder are too large? Would not drill out holes. I would find decent used pots before I did that. Lpads are least expensive and most reliable route if they will fit. Adams Quote Link to comment Share on other sites More sharing options...
mondo Posted December 29, 2019 Author Report Share Posted December 29, 2019 Thanks for the response! Here’s a picture to illustrate the difference between old and new. Quote Link to comment Share on other sites More sharing options...
Aadams Posted December 29, 2019 Report Share Posted December 29, 2019 Wow! That is a big one. 8 ohm 15 watt lpads are 1.5 inch diameter and a snug fit side by side in a 3a box. Threaded stem diameter is near identical to pots. Some members here have used what you are showing as 3a pot replacement so maybe there is a difference in the mounting hole displacement between a 103 and a 3a or they made mods to the masonite holes. If you use Lpads with 1" inch stems you can make use of "air rights" inside the box and have more room for wiring and other pieces to run in the horizontal plan. Setting stem height is easy with supplied spacer washers and nuts. Quote Link to comment Share on other sites More sharing options...
ra.ra Posted December 29, 2019 Report Share Posted December 29, 2019 Take a look at this current thread which uses robust foreign pots which are about 1-3/8" diameter. Quote Link to comment Share on other sites More sharing options...
RoyC Posted December 29, 2019 Report Share Posted December 29, 2019 If the control shown in the photo and in the Ebay link provided by the OP are the same, they should work satisfactorily. I have one here (provided by forum member Chris1this1) and it is the same diameter as a 15 watt L-pad, which is just a bit over 1.5 inches. Unless, as Aadams suggested, the 103 has a different mounting distance between the controls...? Roy Quote Link to comment Share on other sites More sharing options...
RoyC Posted December 30, 2019 Report Share Posted December 30, 2019 If the level control in the photo is not the same as the control in the provided link, more information is needed to be of any assistance. Roy Quote Link to comment Share on other sites More sharing options...
JKent Posted December 30, 2019 Report Share Posted December 30, 2019 very odd indeed. The listings for the replacement pots give the diameter as 40mm which, as Roy said, is just a tad over 1.5" Quote Link to comment Share on other sites More sharing options...
mondo Posted December 30, 2019 Author Report Share Posted December 30, 2019 I think it is safe to say that the 103 does have a different displacement between mounting points for the pots. It's only about a mm or two too short for these to work, unmodified. I'll measure the distance later today and report back. Thanks for the help, friends. Quote Link to comment Share on other sites More sharing options...
Chris1this1 Posted December 30, 2019 Report Share Posted December 30, 2019 I agree that spacing on the Heathkit could different. They fit in the typical AR installations, as pictured in a pair or AR3's, with about 1/8' to spare. ?♂️ Quote Link to comment Share on other sites More sharing options...
lakecat Posted December 30, 2019 Report Share Posted December 30, 2019 There is a difference. The Heathkits are spaced 1.5" apart....the 3a is 1.75". Maybe rounding out each hole just a little to the outside will make them fit. Quote Link to comment Share on other sites More sharing options...
ra.ra Posted December 30, 2019 Report Share Posted December 30, 2019 This pic using foreign pots is from the thread I tagged earlier, which makes no mention of altering the original attachment plate. Quote Link to comment Share on other sites More sharing options...
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