DIY Secondary Heater 200P??

[catman161]

Right, I have posted this on other forums (EMS, Astronomy Shed) but I want to get as wide an opinion as possible as I have seen many ingenious ways people have come up with to combat the arch nemesis that is Dew! The other weekend at a darksite in Belper a couple of weeks ago made me realise that I need to invest in dew control. So I will be getting some things over the next month or too like dew heater strips and 4 port hub etc most probably very similar to the setup a fellow EMS member Daz has as he was kind enough to let me know dew strip sizes and other items etc as we have a similar setup. They seem to work very well for him so why go different when I know it works

What I cannot find is a ready made secondary mirror heater for the 200P. I know some people have made their own, another fellow EMS member Martyn built a fantastic one for daz, which looked great. So what I want to do is make one too. However having no idea where to begin I thought I would ask you all

So what do I need to get and how do I put it all together?

Any advice would be gratefully received. Bear in mind that I have no clue when it comes to electronics so please bear with me and the inevitable questions-sorry. Thanks in advance

[Rustysplit]

I use a dew heater strip wrapped around the metal support stalk on the secondary with the wires to it taped along the top and bottom of the spider vanes. Does the trick perfectly.

Just make sure that you wrap the heater band nice and tight and that no part of it projects beyond the edge of the secondary mirror.

[catman161]

Ahh, I hadn't even thought of that option. Thanks for that-I just assumed that the resistor would need to be in direct contact with the secondary mirror back. Food or thought definitely

[earth titan]

You can buy ones which fit under the secondary mirror but not sure they are specific to that scope.

My plan for my secondary on my LB when I get time, is to silicon a resistor to the back of the secondary and put a variable resistor in line to allow temperature control.

Only needs to get vaguely warm for it to work.

Typed by me on my fone, using fumms... Excuse eny speling errurs.

[catman161]

You can buy ones which fit under the secondary mirror but not sure they are specific to that scope.

My plan for my secondary on my LB when I get time, is to silicon a resistor to the back of the secondary and put a variable resistor in line to allow temperature control.

Only needs to get vaguely warm for it to work.

Typed by me on my fone, using fumms... Excuse eny speling errurs.

That's what I intend to do but am more looking for guidance on what type of resistor is needed and what I need to buy (supplies wise) and then the process of making it really.