[QuadList] Recortec timer issue

[LARRY]

Guy,
One other odd thing I just remembered:
The power supply for the recortec needs to be between 4.7, 4.8 vdc.
The book makes mention of this.
It seemed a little on the low side for TTL, but may be something else for you to check out.
I guess if the DC supply voltage varies too much from the book spec, the clock pulses' one shots timing will also vary.

That sorta reminds me of something like III would do. They built a whole PDP-10 DEC clone page CPU and ajusted all the one shots without bothering to first check the +5v supply.It wasn't: was 4.81 volts, and all the ones out on sites had to be run at 4.81 vdc.
I know its not a big detail, but it's sometimes little stupid nit picky things like this that might keep stuff from working.
larry

----- Original Message -----
From: "Guy Spiller" <quadruplex at verizon.net>
To: "Quad List" <quadlist at quadvideotapegroup.com>
Sent: Thursday, September 22, 2011 7:24:48 PM
Subject: Re: [QuadList] Recortec timer issue

Larry,
Did yours just suddenly quit counting completely, or was it somewhat 
intermittent...perhaps with temperature?
Guy

On 9/22/2011 6:30 PM, LARRY wrote:
> Hi Guy,
>
> If Ted can't find his manual, I got one.
> I just fixed the one on the TR-70c here a few months ago. One of the phototransistors went bad underneath the roller.
> Good luck finding a replacement! We were lucky to have another one in a non-fuctioning unit.
>
> Larry
>
> LE Odham
> Engr/Tech
> TAMIS Archive
> Knoxville, Tenn.
>
> ----- Original Message -----
> From: "Guy Spiller"<quadruplex at verizon.net>
> To: "Quad List"<quadlist at quadvideotapegroup.com>
> Sent: Thursday, September 22, 2011 4:30:44 PM
> Subject: [QuadList] Recortec timer issue
>
> The Recortec timer that was installed on my TR-70C suddenly stopped
> counting on machine powerup last night.  Just sits with all zeros.
> I have no documentation for this thing, as someone installed it after
> the fact, and no experience with Recortec timers at all. All my quads,
> "back in the day" had mechanical timer/counters.
> Do these things have a historically common failure mode?  Is there a
> lamp/photocell/slotted disc arrangement and possibly just a failed lamp?
> I haven't opened it up yet, but I thought I would check the vast
> knowledge here on the list and see if I can get some idea what I'm
> getting into before I take the machine offline to deal with it.
> thanks
> Guy
>

-- 
Guy Spiller
email: quadruplex at verizon.net
phone: (804) 379-2050
website: www.GuySpiller.com
Midlothian, VA


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