[GreenKeys] Need advice - 28 selector almost works OK

[Don Robert House K9TTY]

Hi Nick,

The manual shows how to check the spring tension for the selector armature. Also the down-stop adjustment.
As I have written many times.. the faster the data rate the more critical are the adjustments and lubrication.
All of us that repaired these machines for the Bell System carried a small envelope with strips of high-grade bond paper.
The strips were about 3/8" wide and about 3" long.  The paper was about 22-24 Pound stock.
These strips are inserted between the selector magnet and the armature.  Hold the armature up and pull out the paper strip.
Keep doing this until the strips come out clean "as a whistle" (whatever that means.)
You need to make sure there is no oil or grease, or anything else in that important gap.
If I find my package of strips I will post an image.

Memories,

Don
K9TTY

P.S.  Let me know if you need a spring gauge.


On 27 Feb 2015, at 9:32 AM, Nick England wrote:

> For my multiple reperf project I've been checking out several typing reperf units that I got from an estate.
> After cleaning, lubricating, replacing lost springs, etc. all except one seem to work fine at 100wpm
> One seems to have a selector problem but I'm inexperienced enough to wonder what to do next - I appreciate some advice from you guys who have serviced 100's of these things.
> 
> Symptoms - bit errors every now and then. When I test with reversals there is a very narrow range on the rangefinder where the tape looks OK almost all the time. Otherwise I get some holes always marking or always spacing.
> 
> I can't *see* anything like missing springs or bent levers or congealed crud in the innards - Adjusting the magnet armature spring doesn't seem to have much effect in increasing the rangefinder range. What else can I actually do in the selector? Is this the symptom of a worn cams or selector levers? 
> 
> Sorry to be such a pest - I just need a retired TTY repairman to move in next door and then I'll be all set to learn something. Until then Greenkeys is my resource - many thanks for all the help and friendly advice.
> 
> Nick England K4NYW
> www.navy-radio.com
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