CB magnetic handset mod

[silverbullet]

Here's a practical mod to your handset which means no blindly fumbling for the handset clip when you should be concentrating on the road. I thought it up for the syncro, so the handset can be snatched up and put down without a second thought. As long as you have a bit of steel dash panel in reach and not covered by a dash tidy or padding, it's viable.
The gist of it is: the high-strength magnet from inside a "staywell" automatic catflap tag (the bit that the pet wears on it's collar - available as spares or find somethihg similar), placed on a steel disc to prevent the magnetic flux affecting the handset. The punch-outs on conduit boxes are ideal, use 1 or 2 together. A washer won't do as the magnet will not sit in the middle.
Glue the magnet and disc onto the handset, magnet outwards where the clip button would normally fix. I used araldite.
Next make up a ring of wood or hard engineering plastic to surround the magnet and exactly the same height and bond to the handset (something around 35-40mm diameter will do just fine, I used a bit of Acetal as it bonds well but PVC or hardwood would work ok too)
I used a black polyurethane sealant as it is slightly flexible and SLSTABB, completely "potting" the magnet in the sealant and smoothing over with a wet finger.
This ring gives the handset some stability and stops it "falling over" and slipping down the dash.
Proven offroad on the recent Surrey Lanes day with syncronauts. Job done! Picture to follow but it shouldn't really be necessary, should it?

[kevtherev]

Top tip...

[silverbullet]

Why thankyou...one for the Wiki?

[kevtherev]

Dunno.. But I'm fixing mine in as soon as possible

er, any chance of some directional pics?

[silverbullet]

I'll take one of the finished article tonight - it's pretty obvious once seen.

[silverbullet]

This works well for me offroad as the set is mounted on top of the dash, over the speaker grille and the handset sits between that and the instrument pod. The flexi-coil droops over the difflock knobs but misses the heater controls and it's not been a problem so far.
You can clearly see the magnet in the middle, the plastic ring and the PU filling the space between:

CB magnetic handset.jpg

[kevtherev]

great.. thanks pal
Very clear on this now

[silverbullet]

No worries - I was just pleased that it worked at all!
If you find a source for high-power magnets like these, let me know as I might run up a few ready-to-go glue-on kits

[v-lux]

Just a thought?

Given that a Microphone is kind of like a speaker in reverse, do you think a high strength magnet might have some detrimental effect on the handset over time?

[dansimpson]

Just a thought?

Given that a Microphone is kind of like a speaker in reverse, do you think a high strength magnet might have some detrimental effect on the handset over time?

Used these alot back in the 80s, never had and probs with microphone degrading, same principle, but the mod shown will work better as you dont have to fish around trying to hit the clip

http://cgi.ebay.co.uk/Magnetic-Mag-Mic- ... 0526545297" onclick="window.open(this.href);return false;

Dan

[silverbullet]

Just a thought?

Given that a Microphone is kind of like a speaker in reverse, do you think a high strength magnet might have some detrimental effect on the handset over time?

That's why I said put the conduit box "punch-out" disc on the back of the magnet, to return the magnetic flux. Having done that, it wouldn't stick to the side of our fridge that way round, so I guessed that it pretty well shields the mic from the magnet.

[Mocki]

most of the microphones used by anyone on here will be "electret insert" not moving coil so shouldnt be an issue.

Many years ago "K40" marketed a microphone with a huge magnet on the back , just as has been done here by SB
they were renound for going faulty, it was a moving coil microphone insert, and the magnet killed it over time.
Biggest issue will not be damage to the microphone, but potential electromagnetic damage to digital media nearby, ie memory cards ( camera, sat nav, phone ect) and to any rewriteable media, memory sticks ect which maybe in near area....and LCD screens ..... be aware of the damage magnets can do.

[silverbullet]

Thread revival! Max's handset expired on the Devon syncro weekend (broken wires caused by no clip, handset draped over dashtop rig) so I loaned her my one as we were homeward bound.

Took the chance to take some fresh pics of what goes on inside a Midland handset and the latest on the magnets etc.

The latest type of Staywell cat flaps are a little rotund mouse shape, pop them open with a blade (clipped together, no glue or plastic welding) These came out a bit dim on macro:



Inside is the magnet and a steel pellet, magnet on top here:



Handset opened up showing the substantial steel plate inside, approx 2.5mm thick so no worries about the magnet affecting the mic after all:



I am now trying to find a source for the magnets wholesale so that I can develop a universal kit...

PS Max's broken wires:

[R0B]

You could use something like these.Only problem is they are that strong you could pull the dash off when picking the mic up
http://www.ebay.co.uk/itm/5-Very-Strong ... 231fb2d360" onclick="window.open(this.href);return false;
http://www.ebay.co.uk/itm/50-Neodymium- ... 53ee1d420b" onclick="window.open(this.href);return false;

[silverbullet]

Ta R0B, looks like there are several magnet sellers on the old 'bay. At least one of them actually lists the rated vertical and horizontal pull force for the magnets, so I'll do a test with the one I've got and an angling spring scale as the catflap ones seem just right. My handset is rock solid when bumping around offroad but you don't have to be a Belrus shot-potter to pull it off the dash