开云体育

-------- Original message --------From: "Jared Cabot via groups.io" <jaredcabot@...> Date: 1/1/21 10:31 PM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] I built a TM500 mainframe tester, and updated the design. Someone might find this useful? On Sat, Jan? 2, 2021 at 06:29 AM, Larry McDavid wrote:>> Note that Jared has updated the main PWB Gerber file and the Instruction > Manual file; if you downloaded those earlier, you need to get the new files.> > Jared and I are discussing how best to order these sets of PWBs. He is > familiar with the ordering details specifying board material, plating > and edge chamfering so I welcome his support on this. I will order the > board sets and repackage and ship them to those who commit to the > purchase. The produced boards should look like those in his YouTube video.>One small addendum to this, the PCB's will likely not be black as that is a premium option that adds significant cost. They will most likely come in the usual green (more period accurate! :) ) to save as much on cost as possible.In all other respects they will be identical to what is seen in my video and what is in my hand now. I have also confirmed my design is 100% operational and working correctly on multiple mainframes now.I'll talk to my contacts at PCBWay to see if I can cut a deal for us, but we'll have to be patient for a few days for them to return from holiday.If we were to simply order say 20 sets of the 4 boards with no other discounts etc, it looks like a ballpark figure will be around $35 per set of 4 PCB's, plus additional local shipping etc from Larry as an additional cost.This includes gold plating on the main PCB, and hard gold on the edge connector fingers for added durability with the required chamfering (My PCB just has standard gold all over, so the hard gold is an upgrade).Obviously, the more we get in on the buy, the cheaper it'll become per set.As Larry stated, we'll be working together to get this all sorted as smoothly as possible. :)On Sat, Jan? 2, 2021 at 01:44 PM, Michael W. Lynch wrote:>> Jared,> > Is there a way to easily bring the EBC of each pass transistor to the front> panel?? These transistors are items that often fail and need to be tested,> especially on these old frames.? Not trying to throw a wrench into the works,> but those pass transistors are a major point of failure and they can cause all> sorts of damage to the plug ins when they are bad.? Even if you could add some> pads near the appropriate connections at the rear to allow those of us who> wanted to add such functionality at our option?> > -- > Michael Lynch> Dardanelle, ARIt would require a redesign as you would need to install switches to isolate the transistors for testing, and provide connectors on the front panel etc. so It is out of scope for this project.However, I do have an extender cable project in the works of which it would be trivial to add some test points for the transistors. Stay tuned. :)On Sat, Jan? 2, 2021 at 09:42 AM, Dave Casey wrote:>> I have one of the originals, and it is almost certainly "Tek" built as> opposed to built from the plans. For one thing, it has a Tek serial number> label and silkscreened front panel.> > Dave CaseyWell there you go, I stand corrected.Actually, thinking about it just now, I do remember seeing some photos of these units around that looked a little more professionally made than any DIY unit.On Sat, Jan? 2, 2021 at 09:39 AM, Dave Casey wrote:>> I believe the notch filter could be built in any form factor. IIRC it does> not use power from the mainframe, so there's no reason it has to be in a> TM-style enclosure.> > Dave CaseyThis is absolutely correct, I think it was built into a TM500 enclosure for user convenience as it was used solely with the SG505 oscillator IIRC.No reason not to save costs of a TM500 enclosure by sticking it into anything vaguely box shaped available to hand. Tupperware? :D