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Dew-Not Aren't Your Typical Heater Straps

Posted by Paul Atkinson   07/15/2004 00:00:AM

Dew-Not Aren't Your Typical Heater Straps
[ARTICLEIMGL="1"]Have you ever used a product and always thought that although it was good, there could be something better? I have. One of those things has been my dew heater setup. Although it works, I always wished there was something just a little more economical both monetarily, and from a power consumption standpoint.

Until recently, I had depended on the Kendrick heater straps to keep the muggy Florida dew at bay long enough to try and make it through a night of 100% humidity. This can be a formidable task using something that has as much glass as the corrector of a C14.

The Kendrick heater strips work exactly as advertised. However, one thing that always bothered me was the incredible amount of power they draw. Of course I had nothing to compare them too, so I simply accepted that a 14” heater for my C14 should draw 4.75 amps an hour if I had to run it full blast. Using batteries that eats up a lot of power really FAST and if you use multiple strips you can use a 100 amp hour battery in mere hours.

I happened to be browsing a related astronomy yahoo user group when I saw a post about a new product called Dew-Not. Reading the post I learned that these were a new heater strap available to the amateur astronomy market. I ventured to the site, liked what I saw, and bought several of them. After using them for a few weeks now, I am so impressed I decided to write mini-review on them. [Note: Dew-Not does not offer any type of controller so you will still need a Kendrick, Dew-Buster or similar product to plug the heaters into as well as a 12vDC power source.]

Dew-Not heater straps are made by a company named AFAB located in Massachusetts. AFAB has been involved in the design and manufacture of resistive heating elements for over 20 years. John Marstiller, AFAB's owner, is the author of multiple patents relating to resistance heaters, methods of their manufacture, and innovative flexible, electrical circuitry. Having now talked to John via phone and through email, I can say that he is VERY knowledgeable, very responsive, and a pleasure to deal with.

Information per the Dew-Not website:

“Proudly made in the USA, the Dew-Not Dew Remover is a thick film heater manufactured for operation at 12 volts. 60% percent of the surface area is heat emitting - this means more even heat distribution and no localized hot spots or burnouts often associated with resistance wire heaters. Protected by over 30 USA and international patents, and carrying more than 20 years of constant improvements and enhancements, the Dew-Not Dew Remover is the ultimate in reliability and efficiency. Dew-Not is available for all popular sized telescopes and custom sizes are available upon request.”

So exactly what does this mean? Well for starters it means you use a lot less power. In simple terms the Kendrick design has a large amount of rubber involved as well as the fabric overlay. The result is that you must heat the rubber and the fabric before any heat is transferred to your OTA or device. Thus, as per my example stated above, a 14/16” Kendrick heater draws a whopping 4.75 amps at 100% power. By comparison, the Dew-Not 14” strip with it’s unique design only draws 1.92 amps at 100% power. The 16” strip they offer only draws 2.15 amps at 100% power. That is a HUGE power savings. You will find a similar differences in amperage required between the two with the Dew-Not power requirements being considerably lower in every size available. My old setup needed 11.75 amps at 100% power using the 4 Kendrick heaters I own. Buying the same size heaters from Dew-Not my maximum power requirement is 5.23 amps at 100% power. That less than half the amperage of my previous setup. It obvious if you do the math that these save a lot of power and will make my 100 amp battery last a whole lot longer!

Dew-Not are extremely well made. On the outside the Dew-Not looks very similar to the Kendrick. They come wrapped in a fabric similar to the Kendrick’s with a Velcro strip for securing the heater to your scope. Each also comes with a 6 foot cord which is 2 feet longer than comes on a Kendrick. This is big difference. Having a C14 I found myself limited to where I could put the heater control so that cord would reach. With an OTA length of 39 inches the 48 inches of the Kendrick didn’t go very far. Also, each Dew-Not cord is individually identified on the plug. For people like me with cords all over the scope that is a nice little added touch when I am trying to determine what I have plugged in or powered up. Lastly, they come with the same RCA male plugs that allow them to be used with all the currently available commercial dew system controllers.

One really neat product they have is a binoviewer heater. This is two properly sized strips (one for each EP) but Y wired down to a single RCA plug. This saves on your outlets and the number of cords you have draped all over. If you binoview the planets like me, you’ll really like this.

Lastly, I have to mention the price. These are WAY cheaper than the Kendrick. For example the 14” Kendrick heater goes for $90+ on most sites. However, the same 14” Dew-Not retails for only $42! Talk about saving some money. I bought a 4” ($24), a 6” ($28), a 14” ($42) and a 16” ($44). Add the shipping which is a flat $7.99 within the USA and I spent $145.99 for everything. The same size heaters from Kendrick would run you $289 NOT including your shipping (the Kendrick were priced with an online dealer). That is almost double!! You save twice the money but sacrifice none of the quality as far as I can see.

You can get more information and order Dew-Not online at and contact John Marstiller directly. His site also accepts credit card payment. Shipment is prompt and professionally packaged and mine actually arrived 2-3 USPS priority, however, I don’t know if he ships everything that way.

In closing, I’d have to say that AFAB has a winner here when the word gets out about their Dew-Not heater strips. Do Kendrick heaters work. Absolutely and have for years! But now you have a choice. If you want to save money, save power, and get an excellent product then you Dew-Not want to pass up the opportunity to check these out.