I am really not familiar with this stuff, but I do recall there is a micro/limit switch on the K/KT/T mechanical knob shaft. I wonder if that is involved in this (ie to short the keyboard)? Have you checked that switch?

73 Eugene W2HX
My Youtube Channel: https://www.youtube.com/@w2hx/videos

From: [email protected] <[email protected]> On Behalf Of Nick England
Sent: Thursday, February 29, 2024 5:43 PM
To: Greenkeys <[email protected]>
Subject: Re: [GreenKeys] 28ASR "T" mode problem

Several people have asked if T mode just shorted out the keyboard signal generator instead of mechanically not tripping it.

No - this is mechanical and not electrical. The perf will cycle MUCH faster than the printer, so you are not restricted to 60wpm when cutting tape in T mode like you are in KT mode.

I just made a video of my other 28ASR punching tape in KT and in T modes so you can see and hear the difference.

It looks like YouTube now does some weird scheduling thing so this may not be visible until midnight.

https://youtu.be/Nv1skylEaKE

BTW, that switch is for controlling an indicator lamp.

Nick England K4NYW
www.navy-radio.com

On Thu, Feb 29, 2024 at 2:55 PM Nick England <[email protected]> wrote:

In "T" mode, the keyboard signal generator clutch is not supposed to engage, meaning that the keyboard mechanically activates the perf but does NOT transmit a signal on the line. This allows you to cut a reply tape without interference while the page printer is printing an incoming message.

My problem is that the perf is getting activated/reset fine in T mode, but unfortunately the keyboard signal generator clutch is also getting tripped, causing the keyboard signal generator to interrupt the signal line. This means I can cut a tape OK, but that printing of an incoming message gets garbled.

I can't figure out how to adjust  the keyboard control selection lever so it does not trip that clutch. The control cam is causing the perf to activate/punch/reset correctly in T mode, and I can see that the keyboard control selection lever is rotated, but that dang clutch trip lever is still tripping.

 Note - I can't actually see the end of the clutch trip lever as it is buried in there somewhere.

 - reference position C on Figure 21 of 573-117-100 - (diagram attached)

Any suggestions? I swear this thing used to work properly but something has happened and I can't figure out what.....

Nick