Re: [midatlanticretro] RK05 battery pack for emergency head retraction
- -------- Original Message --------
> From: "David Gesswein" <djg@...>retraction
> Sent: Friday, December 28, 2012 9:30 AM
> To: firstname.lastname@example.org
> Subject: Re: [midatlanticretro] RK05 battery pack for emergency head
> On Thu, Dec 27, 2012 at 11:08:08PM -0500, B. Degnan wrote:
> > Found from the manual that the batteries are associated with the H743
> > voltage regulator.
> > t_72.pdfnever
> > thanks for the tip, I do run the system somewhat frequently, but I
> > thought about the batteries in each drive's power supply system. Theyaddress.
> > probably will not leak unless they're incredibly old, I *assume* the
> > previous owner replaced them, but I will make this a priority to
> They are nickel cadnium so will leak after enough time though not as bad
> as some other types and only metal below them. The origional has a
> sleve around the entire pack which also contained most leakage. Nexttime
> I replace them I probably will see if supercaps will provide enoughenergy
> so the repair is permanent.By the way, thanks for the great web site, I really appreciate the time and
effort put into putting all this together...I am getting closer to having a
"DEC teletype" set up, by following these directions
Right now my teletype is stock, and only capable of receiving, but at least
that part works great now.
- On Sun, Dec 30, 2012 at 02:31:11PM -0500, B. Degnan wrote:
> By the way, thanks for the great web site, I really appreciate the
> time and effort put into putting all this together.
> I am getting closer to having aI was recently looking at that and either missed it or didn't see the
> "DEC teletype" set up, by following these directions
schematic for the 4915 board.
I did find a version here
The free version of Eagle will dispaly them. I put a PDF copy here in
case you don't wish to download Eagle.
I was reparing some of my spare cards and noticed that the reader run
drive signal was going way negative at turnoff. When I originally did it
many years ago I didn't put a diode across the relay coil. Adding that
made it stop abusing the drive transistor.
> Right now my teletype is stock, and only capable of receiving, but at leastThats good. Hopefully you will have it fully functional. It should
> that part works great now.
transmit without the mod, just the paper tape reader may loose characters
and won't turn on automatically.
Those bus bars they used on cards for power distribution are annoying
me. One card had an intermittent where one of the pins has bad solder
joint. Another card several of the pins were broken off entirly that
was a pain to fix.
- On 12/30/2012 04:15 PM, David Gesswein wrote:
>> By the way, thanks for the great web site, I really appreciate theSeconded! It's great stuff. In fact when I first met you in person
>> time and effort put into putting all this together.
at VCF-E in 2011, I felt a bit of "celebrity shock". :)
Dave McGuire, AK4HZ
New Kensington, PA
- On Sun, Dec 30, 2012 at 04:15:19PM -0500, David Gesswein wrote:
> It shouldThis may have been unclear. It is referring to the reader run mod. Teletypes
> transmit without the mod, just the paper tape reader may loose characters
> and won't turn on automatically.
had lots of options so it can be configured such that it doesn't work. The
teletype does need to be set to passive transmit loop (just contact closure).