Scope soldering iron - Page 1
Forum section: electronics / general

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: July 26, 2015, 10:30:29 am
content: A friend brought his soldering iron round for me to look at as it had stopped heating. I have marvelled at this iron before and initially was convinced that it was some form of 'pyrograhic pen', and have had heated discussions trying to persuade him to replace it with a 'normal' temp controlled station. He does not often use it on PCBs etc but mainly for repairing wiring and soldering battery packs. The iron is a true horror that is controlled by a lever that pushes a carbon rod into contact with the tip and return circuit. It is powered by a 4VAC transformer. The heating is achieved in the carbon rod which transfers directly to the short tip. The tip will glow red very quickly with a press of the lever.I have found one reference to this Australian iron on EEV blog, but I wondered why it was designed thus, and why 50 years on it is possible to buy spare parts for one. They are not cheap !BT

author: SeanB
author_rank: Super Contributor
timestamp: July 26, 2015, 11:10:16 am
content: Just buy a simple soldering gun for the battery packs, a small 100W one for most wiring ( I have used it to do SMD replacements of resistors and diodes, it works for a small limited range of working) and a 150 or 200W Bosch ( the one I bought on auction) for those massive connections that most soldering stations will never handle ( Metcal aside with the insane heat transfer capability), and for those which are more plumbing than soldering get a MAPP torch and use that.The Bosch will heat the tip up to red heat, I have used it to light candles, weld plastics together, cut into plastic boxes, etc. Tips are cheap as well, just a hammer and a handy 1m length of steel plastic coated fencing wire as the lifetime supply of replacement tips.

author: BradC
author_rank: Super Contributor
timestamp: July 26, 2015, 11:23:20 am
content: I learned to solder on a SuperScope and graduated to a MiniScope (the one in your picture) for my 6th birthday. I still have it although it lives in Dad's garage. I did *plenty* of digital electronics with that iron before I moved on to a Hakko Station at 15. With the right lever action you could keep it just above the melting point of solder, through to red hot for plumbing work.Don't knock it till you've spent some time with it.The biggest issue for me was the un-plated tips which you got through pretty quickly (relative to plated tips anyway).

author: vk6zgo
author_rank: Super Contributor
timestamp: July 26, 2015, 02:00:09 pm
content: The "Scope" iron was very widely used in Australia for general vacuum tube equipment repairs,& with care in its use did a very good job.An important feature was that it could be used for heavy work,which would otherwise need a massive directly mains operated unitIt could also be operated off a 6v car battery,for use away from the Mains---an important point in the 1950s.The "Miniscope" was an attempt to produce a smaller unit more appropriate for PCB work.It was never quite as reliable as the full sized unit.Keeping the "barrel" threads clean,& replacing the carbon elements regularly was essential for reliable service.

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: July 26, 2015, 02:57:26 pm
content: Thanks for the replies- I can see now that my criticism of my friend's iron was perhaps a little hasty. We all need a large iron for the occasional high power jobs. I have an ancient Henley 60W hanging in the shop; it is known as 'The Big Bogger' and it resembles a small cricket bat with a mains lead. Recently I acquired an Aussie-made Birko 65W (the company also made tea urns !)The 'Scope' iron had eroded the carbon so that it no longer contacted the copper tip. It has been returned to it's owner and he tells me that he is to terminate its tenure with him.BT

author: Unknown
author_rank: Unknown
timestamp: July 27, 2015, 12:53:09 am
content: Quote from: BradC on July 26, 2015, 11:23:20 amYeah, this. They're pretty agricultural in method, but they definitely have their uses. Think of them as the Metcal of the time, whereyouprovide the feedback!In their day the orginal Scope/SuperScope irons were what every electrician / auto electrician lusted after - you could solder everything from indicator lamp wiring all the way up to a stud rectifier tab or chassis connection without changing tools or tips. Back in my Telstra days I once used the same iron I'd been using all day to do grading (~0.8mm wire on tags about the size of the ones in a 1/4" phone plug) to make an emergency repair of a cracked tab on a 500A/Hr cell (~1.5" wide x 3/8" thick chunk of lead) in an exchange battery one night.The MiniScope was definitely more troublesome than the bigger versions, but personally I think it's just the thing for general wiring and battery pack tabs (which should really be welded, but whatever) - better than a big element-heated firestick. I'd recant and suggest he hangs onto it.(I've still got an early black bakelite scope gun & transformer which I use for stuff like that. Easier than breaking out my father's enormous old wooden-handled 120W firestick and waiting for it to heat up, or firing up the Portasol and running out of gas just when the joint's getting hot enough...)

author: tautech
author_rank: Super Contributor
timestamp: July 27, 2015, 01:14:22 am
content: Quote from: BurningTantalum on July 26, 2015, 02:57:26 pmSurely sourcing round carbon rods would not be too difficult.Diameter & length?Old carbon arc torch electrodes?Round carbon brushes?eBay?

author: BradC
author_rank: Super Contributor
timestamp: July 27, 2015, 01:28:52 am
content: Scope tips and elements are still available off the shelf.

author: BurningTantalum
author_rank: Frequent Contributor
timestamp: July 27, 2015, 12:37:03 pm
content: Thanks again. I've passed all the comments on to him, and I think that he is keeping it now!We are aware that the tips and carbon rods are available. Coincidentally, I left him looking at a set of carbon rods for a 'searchlight' welder. He was also talking about stripping apart an old zinc carbon C cell. I went home to my Metcal.BT

author: Richard Head
author_rank: Frequent Contributor
timestamp: July 28, 2015, 07:32:33 am
content: We used to call our 200W Wella "Big Bertha".

author: lowimpedance
author_rank: Super Contributor
timestamp: July 29, 2015, 12:31:16 am
content: I still use both mini and standard size scope irons in addition to JBC and weller multi station setups at work. I have both size scope irons at home aswell as a 936 hakko.They all have thier place to cover the full cross section of electronics contruction. With some gained skill the scope irons work very well and as can be seen with spares still available that there are still plentystill in service.It really is not meant to get to the red hot stage and the result will be damage to the carbon element. Your mates iron looks to be in good shape so really he should stump up for some carbon elements and a spare tip or 2, its worth it even if he decides to get another iron setup.Not sure which suppliers you have looked at but in Sydney WES components have Scope spares and new irons etc.

author: jefft104
author_rank: Newbie
timestamp: July 03, 2016, 07:00:27 am
content: Interesting thread. My partner was cleaning out the garage and came across an ancient transformer....all iron no plastic. It read scope 3.3 volts with a 60 second duty cycle. I googled it and found out it was for a scope soldering iron. I have a newish soldering station which is temperature controlled and after just a few years found out parts were no longer available. Yet here was this antique transformer, well over 50 years old by the looks of it. It came from her dad's estate. He was an electrician. A quick look on the web and found some reviews raving about the scope soldering iron. Sure enough still sold...although the transformer is now all plastic. Parts still available. A quick check of the secondary demonstrated the transformer still put out....at least with no load. Got online and ordered the scope mini from Radio Parts in Melbourne. They have better prices than what was on ebay. Can't wait for it to arrive so I can try this thing out.cheersJeff

author: BradC
author_rank: Super Contributor
timestamp: July 03, 2016, 08:13:53 am
content: The trick is a light touch on the handle/lever. Don't crush the element with too much force and use the smoke from the flux as a good temperature indicator. I even did 1206 SMD with my miniscope. The super scope (same transformer just a bigger iron) had no problem doing car battery cables/lugs.If you can source it, there used to be some leaded solder that had a percent or two of copper in it. That made the unplated tips last longer. I used to buy them and the carbons in packs of 5 at Atkins Carslile in Perth (long gone unfortunately)