Lynx Astro Dew Heaters: Toasty or Frosty?

[Nightspore]

I had some three and four inch Astrozap dew heater straps on order for several months. The retailer recently contacted me to tell me that they are having difficulties sourcing Astrozap heaters. They offered me some Lynx Astro equivalents (apparently with new style heaters), so I decided to purchase those instead.

They came today and appear high quality and well made although their respective sizes stated on the packets are ‘40cm’ and ‘30cm’. Which I assume is some ‘Nasa type’ of metric/imperial discombobulation. They are basically about 100mm and 80mm.

 

 

I decided to test the larger one indoors on my modified 80ED Evostar. The Evostar has a 100mm OTA and requires at least a four inch strap size. I used an Astrozap dual controller and a fully charged Sky-Watcher 12v powertank. The channel to the heater band was turned up to full, with the second channel for the reflex finder heater set to medium. This usually makes the heater strap quite warm to the touch after only a few moments.

 

 

Unfortunately even after several minutes the Lynx Astro strap seemed only slightly warm, and to be honest, a little lacklustre in performance. This may be because the strap outer surface seems made of a moderately thick felt-like material and didn’t feel particularly warm to the touch. The underneath seemed warmer but it didn’t seem as warm as it should have been after only a few minutes. 

 

 

I compared the 80mm strap on my 72ED Evostar and the performance was about the same. Admittedly these are preliminary indoor tests, and the straps don’t need to be red hot, but they were both reminiscent of a similar lacklustre strap I bought from Rother Valley Optics a couple of years ago.

 

Above: RVO strap on my modified ST102

 

The unbranded RVO heater strap doesn't seem to be as well made as the Lynx Astro or Astrozap heaters. I don't know where it was manufactured. I believe they are now discontinued. While using this RVO strap I found the objective of my ST102 would dew over even when the controller was turned to maximum. 

 

Above: In a direct comparison with an old three inch Astrozap strap on the 72ED the Lynx Astro just didn't appear to get sufficiently warm. 

 

However, later I tried the Lynx Astro heater straps with the powertank without putting them around an OTA. This was so I could more easily physically feel the temperature produced by the inside of the strap with my fingers. I was pleasantly surprised to discover that they got quite ‘toasty’ on the inside of the strap. As I suspected earlier the external felt-like material was insulating them somewhat. This has greatly improved my confidence in them. The next step will be to test them in the field (my back garden).
 

[Bottletopburly]

I have a lynx Astro  Eqdirect cable and a mount power cable , well made imo.

[Nightspore]

10 minutes ago, Bottletopburly said:

I have a lynx Astro  Eqdirect cable and a mount power cable , well made imo.

Yes, the heater straps are well made too. Apparently manufactured in the UK. I think they should be warm enough. I'm a little wary since the RVO strap.

[Bottletopburly]

I think that lynx Astro are a flo company 

[+Graham]

I have run a couple of these on my GT 81 for a while now.

Like you I was concerned about the lack of heat on the outside at first but to date I have never had an issue with the scope fogging up and I have had it out in some atrocious conditions.

I think they have a heat reflective material between the element and the outer covering.

Extremely well made as has already been said.

I also pair them up behind the dew shield  on my 150 mac with the same good results.

Cannot fault them in any way.

[Nightspore]

1 hour ago, Bottletopburly said:

I think that lynx Astro are a flo company 

I got them from FLO, so there is probably a connection somewhere. 

 

 

I'm pretty sure one of the aftermarket visual backs on my Evostars was Lynx Astro. Not sure which one though.

 

[Nightspore]

7 minutes ago, Graham said:

I have run a couple of these on my GT 81 for a while now.

Like you I was concerned about the lack of heat on the outside at first but to date I have never had an issue with the scope fogging up and I have had it out in some atrocious conditions.

I think they have a heat reflective material between the element and the outer covering.

Extremely well made as has already been said.

I also pair them up behind the dew shield  on my 150 mac with the same good results.

Cannot fault them in any way.

Thanks for the feedback Graham, that's reassuring. After the experience with the RVO heater band I'm a bit circumspect. They are really well made though so I'm pretty sure they'll deliver.

[+Bino-viewer]

Another dew heater manufacturer i can recommend is W&W Astro.

Nice quality at a good price.

Barbara (the lady in charge) is nice too......

[Nightspore]

7 hours ago, Bino-viewer said:

Another dew heater manufacturer i can recommend is W&W Astro.

Nice quality at a good price.

Barbara (the lady in charge) is nice too......

Thanks, they look good. 

 

https://dewheater.com/