Welcome to the RCA AR88 owners club! 
► Re: the aerial socket fitted to the rear, which is connected straight to a tag on the first I.F can. ◄
That is obviously a modification and is almost certain to be for the purposes of connecting a Q-multiplier.
As regards tuning backlash, yes, a very common problem. When I first got the one I own now, the backlash was very bad. The cure is to remove the gearbox completely, strip it down, thoroughly clean it, re-assemble it - being careful to set up the anti-backlash gears correctly - re-lube and re-fit it.
The rub in all of that is the "set up the anti-backlash gears correctly".
Not an easy task by any means, but I made myself a jig to support the frame and four clamps to hold the gears in their tensioned positions whilst they were refitted: made the task a lot easier. But it is still a very tricky job - and it can be done - just requires plenty of patience, perseverance, a tidy bench - and plenty of time. And don't be surprised, when you refit it, if you find that you then have to remove it and do it all again - because the backlash is still not acceptable 
. Generally speaking, though, an inter-gear tension of about two teeth is usually about right, but it does depend a great deal on the springs - they do tend to become 'tired' with age - and consequently weak. Sad to say, that is a symptom that I personally recognise all too readily! 
Overall, though, when all the necessary 'standard' overhaul work is done (which often is not a lot), you end up with a receiver that holds its own on the S.W. bands, even today, after all these years.
Al. / Nov. 20, 2012 //
► Re: the aerial socket fitted to the rear, which is connected straight to a tag on the first I.F can. ◄
That is obviously a modification and is almost certain to be for the purposes of connecting a Q-multiplier.
As regards tuning backlash, yes, a very common problem. When I first got the one I own now, the backlash was very bad. The cure is to remove the gearbox completely, strip it down, thoroughly clean it, re-assemble it - being careful to set up the anti-backlash gears correctly - re-lube and re-fit it.
The rub in all of that is the "set up the anti-backlash gears correctly".
Not an easy task by any means, but I made myself a jig to support the frame and four clamps to hold the gears in their tensioned positions whilst they were refitted: made the task a lot easier. But it is still a very tricky job - and it can be done - just requires plenty of patience, perseverance, a tidy bench - and plenty of time. And don't be surprised, when you refit it, if you find that you then have to remove it and do it all again - because the backlash is still not acceptable . Generally speaking, though, an inter-gear tension of about two teeth is usually about right, but it does depend a great deal on the springs - they do tend to become 'tired' with age - and consequently weak. Sad to say, that is a symptom that I personally recognise all too readily! Overall, though, when all the necessary 'standard' overhaul work is done (which often is not a lot), you end up with a receiver that holds its own on the S.W. bands, even today, after all these years.
Al. / Nov. 20, 2012 //
