Subject: SWTPC TV Typewriter II restoration

From: "Michael Holley" <[email-masked]>
Date: Sun Mar 16 22:52:00 2003

A year ago I acquired a Southwest Technical Products Corp. CT-1024 TV
Typewriter II. It was a basket case. The main board was purchased as just a
bare board and the original owner had used what ever parts he had. (SWTPC
clipped a corner on bare boards they sold without a kit of parts.) The
keyboard was an old Keytronics unit.

I wanted to restore it to "factory" condition. My brother had just given me
a nice Metcal soldering station so stripped the main board of all parts and
only lifted a few pads.

Over the next 6 months I collected a complete set of parts. In the last
month I got serious about this project and I have finished except for a new
clear acrylic plastic case.

This unit is now closer to "factory" condition then when it was assembled in
1976 or 1977. All of the ICs are the correct part (7474 not a 74LS74
substitute.) The capacitors new but are the same type as the original. They
tend to be smaller in size then the 1975 versions. I was able to get all new
Molex connectors.

There was a recent flame war on what is new and what is original but I think
this restoration improved this classic computer terminal.

Here are some links to my CT-1024 TV Typewriter II pages.
http://www.swtpc.com/mholley/CT_1024/CT1024_Index.htm
http://www.swtpc.com/mholley/CT_1024/Restore/CT1024_Restore.htm

Michael Holley
www.swtpc.com/mholley

Thanks to Jay West for providing the web servers for www.swtpc.com.

---

From: "Philip Pemberton" <[email-masked]>
Date: Mon Mar 17 01:25:01 2003

Michael Holley wrote:
[snip]
> http://www.swtpc.com/mholley/CT_1024/Restore/CT1024_Restore.htm
Wow. I'm speechless. That is one amazing repair. I think it's high time for
me to smash my piggy-bank, raid my bank account and buy a nice soldering
station :-)
I've just come to the conclusion that my Antex XS is far too overpowered for
repair work. It's great for stripboard (Veroboard) assembly, though. The
solder I'm using has a melting point of 340 C (IIRC). The iron heats up to
450 C (according to Antex) and seems to have no temperature regulation
whatsoever...

Later.
--
Phil.
[email-masked]
http://www.philpem.dsl.pipex.com/

---

From: Bryan Blackburn <[email-masked]>
Date: Mon Mar 17 02:25:00 2003

Excellent work! That's really pretty.

-Bryan

---

From: Eric Chomko <[email-masked]>
Date: Mon Mar 17 07:13:00 2003

Yes, could not agree more! The original CT-1024 terminals were not that
great. The one we had at the shop I worked in at the time displayed the
lines on the screen with a slight vertical ripple effect. Also, the
plastic was so thin that when you picked the terminal up it tended to
give a little. I much preferred a ADM-3 or a Televideo 910. But who the
cash 
for them back in 1976? I didn't!

All in all, still a great project.

---

From: [email-masked] (Tony Duell)
Date: Mon Mar 17 18:35:33 2003

> me to smash my piggy-bank, raid my bank account and buy a nice soldering

Well, I should probably upgrade myself (I still use an old Weller TCP, 
which has a not particularly accurate thermostat), but I can assure you 
that even that is a lot nicer than most 'hobbyist grade' irons. 

To the extent that on the few occasions that I've tried to use a cheap, 
totally non-thermonstatically-controller iron recently (to save going 
back to get my Weller), I've had to give up and go and get said unit.

> I've just come to the conclusion that my Antex XS is far too overpowered for

You probably mean _UNDERPOWERED_ !

Power is not the same as temperature. For example, my Weller is actually 
a 45W unit, which sounds rediculously high (after all, many books 
recomend a 15W iron for PCB work). The problem with too high a power in a 
non-controlled iron is that it gets too hot. The problem with too little 
power (in any type of iron) is that it takes too long to heat the joint 
up, thus getting the rest of the PCB and components hot, causing damage.

Try soldering (or worse, desoldering) an IC pin connected to an internal 
ground plane on a multi-layer PCB and you'll see what I mean

-tony

---

From: "J.C.Wren" <[email-masked]>
Date: Mon Mar 17 18:54:00 2003

There is only one TRUE soldering iron.  If you're serious about soldering
and surface mount, you want a Metcal.  Don't get the SP-200 series, they're
junk.  Used Metcals can be had on eBay.  Avoid the RFG-30 bases, those are
antiques (and not in a good way).  The MX 500-DS is ideal, as you can use
the 2nd port for either another wand, or the Talon tweezers.

	The tips are cartridge style tips, and hold temperature regulation far
better than a Weller or Hakko (I've used *lots* of different irons in
product environments.  Don't tell me how much you love your Weller or Hakko
until you use a Metcal.  Once you've had, you'd just as soon use a wood
burner as go back).  There are well over 100 different tip styles available,
including specialty tips for removing QFP, SOICs, PLCCs, etc.

	The Talon tweezers are really nice for removing SMT resistors, caps, and
with the right tips, SOICs are easily removed.

	--John

> -----Original Message-----
> From: [email-masked]
> [mailto:[email-masked]]On
> Behalf Of Tony Duell
> Sent: Monday, March 17, 2003 18:49
> To: [email-masked]
> Subject: Re: SWTPC TV Typewriter II restoration
>
>
> > Michael Holley wrote:
> > [snip]

---

From: "Philip Pemberton" <[email-masked]>
Date: Tue Mar 18 01:38:00 2003

> that even that is a lot nicer than most 'hobbyist grade' irons.
Hmm... The only Weller soldering iron I've ever used was a 100W soldering
gun. And that thing was crap with a capital C.

> To the extent that on the few occasions that I've tried to use a
> cheap, totally non-thermonstatically-controller iron recently (to
> save going
Hmm... I've always been a fan of the Antex irons. They make an iron known as
the "TCS" - it's basically an XS with a thermostat. Then there's the
full-blown Soldering Stations - the yellow one (without digital readout) and
the black ESD-safe one (with a digital readout). They should both be listed
under "Products" at www.antex.co.uk. The TCS230 is a 50W temperature
controlled iron, priced up at £45. The next one up is a soldering station at
£112...

> You probably mean _UNDERPOWERED_ !
It certainly seems to get very hot, but the temperature plummets when it
touches a joint on a PCB...

> recomend a 15W iron for PCB work).
Right....

> The problem with too high a power
> in a non-controlled iron is that it gets too hot. The problem with
> too little power (in any type of iron) is that it takes too long to
> heat the joint
OK, then. Time to smash the piggy-bank again :-P

> Try soldering (or worse, desoldering) an IC pin connected to an
> internal ground plane on a multi-layer PCB and you'll see what I mean
Been there, done that, bought the T-shirt. That's why I get to rebuild
100-or-so through-holes on the Ace - the soldering iron soldered the THP to
the IC's pin and then when I pulled the IC out, it ripped up the THP... Time
to get the wirewrap wire out again...

Later.

---

From: [email-masked] (Tony Duell)
Date: Tue Mar 18 16:40:00 2003

> and surface mount, you want a Metcal.  Don't get the SP-200 series, they're

That's why I said I should probably upgrade sometime...

> until you use a Metcal.  Once you've had, you'd just as soon use a wood

I will say one thing. For classic computer repairs (0.1" pin-through 
hole, 0.05" SMD), a Weller TCP is perfectly useable. Not the best, but 
useable. I can't remember the last time I lifted a pad or ripped out a 
through-hole-plating 'tube'.

The hobbyist-grade irons are not useable. They will do a lot of damage to 
PCBs!

-tony

---

From: Ethan Dicks <[email-masked]>
Date: Tue Mar 18 16:59:01 2003

> The hobbyist-grade irons are not useable. They will do a lot of damage to

No kidding.  My Cosmac Elf and my TVT-6 look like hell because a) I was
just a kid when I assembled them, and b) all I had was a Rat-Shack 
cheap-ass soldering iron.

Once I got a job at a place that did manufacture/rework, I upgraded to
a Weller (the very same ones I have now ;-)  I've replaced one heating
element and one thermistor (different innards, or I might have combined
the two into one).  Got a problem now where I have to make sure that
the iron really is plugged into the base - the plastic ring is so worn
that it doesn't hold the cable tightly.

I used Metcals at Lucent.  Verrrry Nice.  I would love to find one with
a box of SMT tips for less than a housepayment.

-ethan

---

From: Roger Merchberger <[email-masked]>
Date: Tue Mar 18 17:50:00 2003

Rumor has it that Ethan Dicks may have mentioned these words:

[snip]

>a box of SMT tips for less than a housepayment.

Can they be had with a full set of SMT tips *for* a house payment? If so, 
I'd consider it...Some of those tips are $60+ USD each... doesn't take many 
where just the tips would be a house payment for me, and the cheapest unit 
I found that looked half-way decent (with 1 tip) was around $400USD. I 
can't afford four digits... :-(

At dalbani.com (out of Miami, FL, USA) they have *low-cost* stuff... some 
of it is complete and utter crap, but sometimes it's a decent deal for 
hobbyist stuff. For the store (we don't do a lot of soldering nowadays) we 
got a digital temperature-controlled soldering iron with 6 tips for under 
$90. It actually works pretty well, for the occasional solder-job... If I 
soldered on a daily basis, I'd get *quality* but for the once-a-month deal...

I don't remember if they had SMT stuff, tho.

Laterz,
Roger "Merch" Merchberger

--
Roger "Merch" Merchberger -- sysadmin, Iceberg Computers
[email-masked]

What do you do when Life gives you lemons,
and you don't *like* lemonade?????????????

---

From: Mail List <[email-masked]>
Date: Tue Mar 18 19:06:00 2003

I've done some pretty fine soldering work with my Ungar ( replaceable
elements and tips).  Used a jewelers file to file the tip down to a very
fine point, and have used it to soldered J-leg chips onto surface mount
pads with with excellent results.

Best Regards

---

From: "Andy Holt" <[email-masked]>
Date: Wed Mar 19 00:32:01 2003

> the 2nd port for either another wand, or the Talon tweezers.
What is the problem with the SP-200?

At a recent local auction I picked-up 8 of these for £40 intending to resell
on eBay -
A couple of them don't have tips, the others all have high temperature tips.

Andy

---

From: "J.C.Wren" <[email-masked]>
Date: Wed Mar 19 10:33:00 2003

Andy,

	(This is a reply I sent to someone else that asked me the same question)

	Perhaps I'm a little harsh.  My experience with them is they tend to be
somewhat underpowered for heavier pins.  But my major complain is they use a
different tip series than the MX-500's.  For light work (typically through
hole, SMT), it should work fine.  For soldering TO-220 tabs to ground
planes, I think you'll have problems.  But more than anything, it's making
the investment in tips.  And the tip selection is a lot more limited.  Of
course, if you're buying tips on eBay, the prices are so low that you won't
have a large investment.  Buying tips at retail hurts.

	As far as things going wrong with them, I'm not aware of any particular
failure modes with them.  I also have a lot less experience with them than
the RFG-30 and MX-500 bases.

	--John

> Behalf Of Andy Holt
> Sent: Wednesday, March 19, 2003 01:26
> Subject: RE: Soldering Irons (was RE: SWTPC TV Typewriter II
> restoration)
>
>