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Thursday 31 March 2011

Turn a soldering station into a reflow tool, using an old aquarium pump and length of silicon tube a bit of wire wool.

I have just replaced my old soldering iron (Maplins N78AR
( solder station) it is 50W
so great for big PL259 connections and making PCB enclosures, has a grounded tip
and it does have spare precision tips too... they have it on special promo right
now for £14.99 which was half what I paid originally. I find the 1mm fine tips
are fine for SMD work.

Anyway the old one the element gave in after 5 years use so I thought try to see if
I can use the old one as a reflow soldering iron instead with a little home-brew effort.

To confirm the element had gone I had dismantled
the old one and I saw that the element and another old iron (Weller maybe?) are
hollow and almost identical construction wise, I have an old fish tank air pump
and just out of curiosity fed some blue high temp silicon tubing (so will not
melt) into the handle base and into the base of the heating element tube. Air
passes up through the tube where it is warmed on the way to the tip which is not
there now just a 5mm diameter hole. The air flow can be controlled with a simple
pinch on the tube with a thumb screw.

I tried this for real and it sort of works, old PC motherboard components reflow
quite easily once set to about 75-80% on the control and adjusting the air.
Adding a little extra wire wool at the tip of the tube seemed to help with the heat
and the dimmer control (basically just a current control) adjusted the air temp.
You turn on the iron, get it to temp and then turn on the air and adjust until
flow/temp is right. The wire wool smoked a very little initially but is fine now, whole thing
almost silent apart for a little hiss and the pump buzz.

Seem to have an extra tool for SMD.

Anyone else done this?

Will post some pics soon.

Monday 28 March 2011

Wobbulator & High gain RF probe

From a Radio Bygones project by Raymond Haig whole 2003 issue can be seen hereI have started to build the wobbulator that I'll use to align the R1155 (probably best known as the RX set in WWII Lancaster) I was given last autumn. Also the partner powered RF probe.

I had a bit of trouble trying to find 400V DC 0.1uF polyester caps (loads at 250V or 285V and a couple at 3KV! I will use .22uF 400VDC ones for now.

The box is still available from Maplin and I have everything else in the 'junk box'. Dave, G4EBT sent me a pair of PCB a while back (hope I did send him a cheque) and I just printed out and laminated the front and will attach to the box lid.

Jabdog came up with the varicap diode and the toko coils and I had everything else.

Will post some pictures..

Wednesday 16 March 2011

Back up and running again, apologies been away for a bit.

After not been able to do anything radio for a while I'm back up and running again.

Last w/e I put in an entry to the BERU contest (Google for RSGB BERU) using a very limited setup. I now commute on the train to work, about 90 mins each way, so finding time to do some research on the latest projects. Lots of QEX issues unopened!

Bit of a backlog of things that need to melt solder on but should have those out of the way soo and then will be ready for a new shack in May.

Thinking about an island trip for RSGB IOTA in July 2011 so if anyone has any suggestions all ears.

Friday 4 March 2011

changing jobs and country so nothing posted for a bit.

Once dust settles and get things unpackaged again will be back melting solder on a few things.

Got the SDR Cube and NuePSk modem to build, there are a couple of FPGA SDR projects I'll be starting on too.