Metcal SP200 : SP-PW1-20
Evening fellow Ratters, hope you're all keeping well and you all have some interesting projects lined up for the festive holidays.
With my workshop completed I'm deciding which TV or perhaps VCR to get up on the bench but before that I decided to treat myself to any early Christmas present.
For the past 10 years or so my main soldering iron of choice has been the Weller TCP series and the DS900 desoldering station. There's nothing wrong with this series of iron, in fact I liked them so much I bought the company.... Not! That's a poor Victor Kiam reference, but if you're of a certain age you may appreciate and perhaps remember the 70's Remington advert. No rather than buy the company, all I did was populate all my workbenches with them and have some in stock for reserve spares. However, there's always a however isn't there, they do play up occasionally with regards to the magnastat element. These sticking and cooking up the tip, I've had to replace one which I guess is not bad considering.
I'd heard rave reviews about a certain manufacturer of Solder station also John (jayceebee) had mentioned this device on numerous occasions in his professional life. The iron I'm talking about is the Metcal series, these irons use their "SmartHeat" system and are used by many professional outfits. I'm sure there are a few of you out there who work in the electronics industry, who are fully aware of these stations.
No dials to set
Each tip cartridge contains a self-regulating heater that senses and maintains a set idle temperature. The temperature is determined by the inherent metallurgical properties of the heater; no external adjustment or equipment is required. The power delivered to the tip automatically varies in direct response to the thermal load. This eliminates spikes and transients associated with electrically switched elements found in conventional soldering irons.
They work by feeding 13.5MHz into the handpiece. The tip has a choke wound on a magnet. When cold, its lossy at 13.5MHz, so heats up. When the magnet hits its curie point the inductance changes and the choke becomes less lossy, so it stops heating up. That results in really good temperature regulation, so you can use little tips without any problems. For those that are not familiar here is a more detailed description, again apologies to those that are aware.
The Basics of SmartHeat and the Heater Elements
SmartHeat heaters consist of two basic elements; a high frequency alternating current (AC) power supply, and a heating element. The biggest difference between a conventional soldering station which consists of a ceramic or wire wound heating element, separate sensor and temperature control circuitry, and a Metcal heater is that the Metcal heating element itself is capable of heating and then maintaining a predetermined temperature. In other words “the heater is the sensor.”
When the Metcal heating element is energized by the high frequency alternating current (AC) power source, the current will automatically begin to flow through the conductive copper core of the heater. However, as the AC current continues to flow, a very useful physical phenomenon occurs, the current flow is directed to the skin of the heater assembly. This is of course known as the “Skin Effect”, it drives the majority of the current through the high resistance magnetic layer, causing rapid heating.
The Curie Point
As the outer layer reaches a certain temperature (which is controlled by its heater alloy formula) it loses its magnetic properties. As most of you know this “certain temperature” is the Curie point. The Curie point temperature is when the “skin effect” begins to decrease again, permitting the current back into the conductive core of the heater starting the whole cycle over again.
The selection of a material with a fixed Curie point results in a heater that will produce and maintain a specific, self‐regulated temperature; and a heater that requires no calibration and responds directly to thermal loads. When a thermal load is applied to the tip, the heater temperature drops and the power supply responds with the power required to correctly solder the joint on the board. In case you were wondering Metcal = Metal Calibration, once built it will never need recalibration. So no more problems with large heat-sinks giving soldering trouble, thermally sucking away the heat, the Metcal station will just keep on providing the energy needed to maintain the desired core temp.
It came with one tip so I've ordered a few more of varying temperatures and tip shape which I'm waiting to arrive. Ouch! They're not cheap, and here was me thinking Weller ones were expensive. I'm itching to test drive it on the festive project, more news of that front in due course once I've made the decision as to what to tackle.
Hope I've not waffled on too much and maybe its been of interest to some.
The paddle in the photo is what you use to remove the tip whilst its hot, before slotting in another tip of choice.
That looks and sounds like an interesting set up. It's not one I'm familiar with, I'm afraid, but the Curie point part of it makes sense, since I have a Weller W101 which has a "temperature controlled" heating element that uses a magnetic switch to maintain the ideal soldering temperature, and uses the "Curie point" to actuate the switch. It uses a "high thermal mass" to aid in smoothing out any tendency toward temperature fluctuation, and the magnetic switch is very precise, with a narrow thermal bandwidth, but they're not cheap!- I guess it's an older technology, but I like it.
A worthy addition to your workshop 👍, certainly the best iron I’ve used. I had quite a range of tips but found the most versatile one for me was the SSC-725A. Down to one brand new replacement left, must order some more 😱.
Like you I have a Weller TCP iron and find it very good. I heard a lot of good reports about the Metcal but to be honest I was sceptical. I couldn't see how it could be much better than the TCP.
A while ago I purchased a second-hand Metcal and recently it got its first proper use doing some surface mount work. I couldn't believe how much better it is. I am converted! It does make soldering easier. The temperature control is noticeably better.
My plan is to use the TCP for general work and "save" the Metcal foe SM work. However long that plan will last 🙄 .
I am sure you will be very pleased with your purchase when you get to try it out.
I have never owned a temperature controlled iron, but there were not many around in the 60’s and 70’s when I was soldering everyday. Mind I was brought up to use a old fashioned, perhaps that should be ancient, type that went on the gas ring or in the coal fire embers. What a luxury to be bought a Henley Solon 25w electric iron when I was about 12 years old. A good thing about having a dad who was very practical was being shown and allowed under supervision at a young age to use hand tools of various types.
Enough waffle from me, I can appreciate the difference a good iron can make, especially in tightly packed circuit boards and SMD work.
A review of how it performs after its been in use for a while would be interesting, not that I need one, it’s been a while since I did any soldering, hopefully the iron is still in the toolbox.
At the other extreme, another iron which I really liked and was very useful on my trips into the field was one of those that you filled with lighter gas. I could have a 1500 dropper out and a new one in before the company electric soldering iron was hot enough. Temperature control was manual though 😊
I used to use one of those back in my first job repairing mobile phones! They were the best iron I’d ever used, though saying that, the only irons I’d used before that were Antex ones or cheapo £3 ones from the local DIY shop. There are a few where I work now, but most are on their last legs and getting thrown out, and being replaced with JBC soldering stations. I have an old JBC station here in my workshop, it’s great! Got it cheap years ago, instant heat up from switch on, goes into a low temperature standby whilst in its stand, and the tips seem to last for ages too. Only downside is the price! Don’t look unless you’re sitting down..
I'm another convert to the Metcal irons since I was introduced to them 5 years ago, the tips are quite expensive but they last for ages heat incredibly fast and it is a doddle to change the tip, you just have to find somewhere to park the removed hot one. Mine is also an SP200.
Big fan of the Metcal Irons... You can solder a penny to a battleship with mine...
This may be of help, if you ever have a supply go pop... https://andydoz.blogspot.com/2017/10/metcal-mx-ps5000-repair.html
I have had a Metcal PS900 for about 10 years. I also have a couple of Antex and a couple of Wellers.
The Metcal stands head and shoulders above all the others.I wouldn’t part with it for all the tea in China
Don’t be tempted to change the tips with the iron switched on. It is instant death to the element.
The rest of my tips arrived today from Farnell. In case you're wondering, left to right
- SFV DRK50 Knife (For IC's)
- SFV CH18AR Chisel (small)
- SFV CH15A Chisel (medium)
- SFV CH25 Chisel (Large)
- SFV CNL04 Conical