Markless ™ Astronomics

Accessories for Big and not-so-Big Dobs

  1. Spider Wiring Kit ™ for Obsession Telescopes ™  

  2. Big Dob DewBuster ™ Bracket     

  3. Markless Distribution Bars ™  

  4. Markless Fan Connection Kits  

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Spider Wiring Kit ™.

Markless Astronomics Spider Wiring Kit ™ for Obsession Telescopes ™

Introducing the Spider Wiring Kit ™ or SWK, for short.   This elegant solution is in response to a perceived need gleaned from posts on Big Dob and Obsession Yahoo Groups.   It is based upon the tried and true method of a single enamel coated wire for one conductor and using a spider vane as the other conductor.   The similarity to the old method stops there, however.   Instead of messy glue, a special tape is used to hold the wire in place.   The tape is strong, black, only 0.0019 inch thick, and is rated to perform in a temperature range of -60F to 300F.   The wiring connections require no soldering and no sanding of the enameled wire.

The kit includes an angle bracket and Phono connector to make connection to your 12VDC supply easy.   It also includes an additional 9V battery clip and mechanical splices in case your DG-1, -2, or -3 dew heater has the new battery box instead of the smaller 9V battery clip.

The SWK comes with every component required to complete the installation.   No need to search Lowes or Home Depot to find a part.   No need to waste hours trying to adapt something to make your installation acceptable.

Price is $31 plus $3 USPS First Class, or $37 if you desire USPS Priority Mail.   Please send me an email to order and specify your telescope model or size.

Specify your size Obsession when ordering.   Write for more details, or to order.

cs(at)marklessastronomics dot com

Made in U.S.A.

Read what customer Bill Warfield had to say about the SWK:

"Charlie, The installation was easy and quick. The directions were good and the photos helped. Now I just have to wait until good weather and a new moon to test the secondary dew guard to make sure all works. I put everything away before I thought of using my multimeter to test it. The powered truss system works fine. Also an easy install. ... Bill"

"Charlie, I finally got my scope together to do the autocal, and took the opportunity to test the the spider wiring per your suggestion. It worked like a charm. What a neat and elegant system. Thanks. ...Bill"

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Dew Heater Controller Bracket, BDDB ™ Bracket.

Dew Heater Controller Bracket (does NOT include BDDB Controller)

Do you have a dew heater controller with a power cord/cigarette lighter combination connection cable? Not exactly Big Dob-friendly, is it?   Markless Astronomics and have collaborated to deliver a dew heater controller and mounting bracket combination that is Big Dob-friendly.   It is called, appropriately, the Big Dob DewBuster (BDDB) Controller.

One of the more useful and unique attributes of the BDDB, besides its many other attractive features (as indicated on the accompanying photograph) is its input power RCA Phono jackwhich permits the user to use his/her own RCA Phono cable to power it.   This eliminates the need to replace the cigarette lighter plug with a RCA Phono plug - a big job for many people.   In addition, the BDDB has three 12VDC unmodulated (straight-through) RCA Phono jacks to power your devices on the UTA that do not require modulated power, eliminating the need for a separate distribution panel on your UTA!   (Hey, whose bright idea was THAT!!? See the DB-3,-4, or -5 on this page.)

Contact Ron Keating at for the BDDB Controller.

Contact me for the BDDB Bracket.

  • BDDB Bracket for classic style Obsessions - $12 plus $6 S&H to the 48 contiguous States. (Does not include BDDB Controller)
  • BDDB Bracket for UC style Obsessions - $18 plus $6 S&H to the 48 contiguous States. (Does not include BDDB Controller)

    Please contact me for S&H to AK, HI, PR, or ROW.

    If you are in North Carolina, please add 7.25% for NC sales tax.

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    Markless Distribution Bar ™.

    Markless Distribution Bar

    The Markless Astronomics Distribution Bar can be used in several different locations on your big Dob or other telescope.   It can be mounted with the Phono connectors pointing vertically as shown, or mounted with the connectors horizontal.   Typical locations (and uses) include

  • On the UTA (to replace single PTS terminal or work with your cable)
  • Outside or Inside the rocker box (power distribution; e.g., use with a RB mounted battery)
  • Inside the Mirror Box
  • Velcroed to the leg of a tripod (expansion sockets)

    The Distribution Bar is designed for 12VDC only.   One Phono connector serves as the connector to the source of 12VDC, the rest serve as output connectors to the devices on your telescope.   Comes with stainless steel mounting hardware.   Models are available with 3, 4, or 5 connectors.   Please specify which model you desire when ordering.  

    There also are switched models called the DB3S2, DB4S2, and DB5S2, which are called switched Distribition-Bar. The configuration is shown in the respective photos.   The smallest version is perfect for mounting on your UTA ring for control of a MallinCam or LCD monitor.  

    A new model has been added called the DB1S1DC1. It's purpose is to limit the current from a DC to DC converter to a laptop. It is internally fused with a 3 amp PTC resettable fuse.   Email me for additional information.


  • DB3       $20       3 RCA sockets
  • DB4       $25       4 RCA sockets
  • DB5       $30       5 RCA sockets
  • DB1S1DC1   $25       1 DC coaxial input jack (2.5x5.5mm), 1 switch, 1 RCA output jack (internally fused with 3 amp PTC resettable fuse)
  • DB3S2   $30       1 RCA input socket, 2 RCA output sockets, 2 switches, each switch is limited to 5 amps, maximum.
  • DB4S2   $35       1 RCA input socket, 3 RCA output sockets, 2 switches, each switch is limited to 5 amps, maximum.
  • DB5S2   $40       1 RCA input socket, 4 RCA output sockets, 2 switches, each switch is limited to 5 amps, maximum.

    S&H is $6 via Priority Mail to USA 48 contiguous States. Please contact me for S&H to AK, HI, PR, or ROW.

    North Carolina residents, please add 7.25% for NC Sales Tax.

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    Introducing the

  • Markless Fan Connector and Switch Kit (FCS1),
  • and

  • Markless Fan Connector and Switch Kit II (FC2S1).
  • Many Obsessions and other big Dobs arrive from the factory with a mirror fan installed, but not connected to power; or, they have a cable with a RCA plug.   However, if that cable is plugged directly into a power rail, it is turned ON and OFF by the switch on the rail, which also turns ON and OFF whatever else is connected through that switch.   The Markless Fan Connection kits are designed to complete the connection AND provide a separate switch to control the fan, at a much more pleasing height above the ground!   Now available, a new kit which requires no wiring at all.  Just mount, plug, and play!!  

    Save your back, get a Markless Fan Connection Kit!


  • FCS1- Fully wired, no soldering required or needed, connects to fan wires with simple mechanical splices. This is the one you need if your fan wires are not terminated with any connector.
  • FC2S1- Fully wired, no splicing, just plug in cables. This is the one you need if your fan wires are terminated with a RCA Phono plug.
  • Easy to install with a single screw.
  • Mounts on the plastic mirror fan plate (Obsessions).
  • Connects to a power distribution device, such as the Markless DistyBar series (DB3, DB4, and DB5), or a power rail.   Use a RCA Phono cable (such as the 3 ft. long Radio Shack SKU 42-2366, not supplied. [2014 Update: RS has discontinued the 3 ft. cable. They still offer the 42-2367 cable, which is 6 ft. long.])
  • Use with 12VDC ONLY!


  • Fan Connection Kit (FCS1) $19
  • Fan Connection and Switch Kit II (FC2S1) $19

    S&H is $3 via USPS First Class Mail, or $6 via USPS Priority Mail.   Please specify.

    North Carolina residents, please add 7.25% for NC Sales Tax.

    Email me at cs(at)marklessastronomics dot com to order.

    Charles Starks, Charlotte, NC

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    Great Astro Links to other fine products and ideas:

    Astrocrumb Filter Slides - a "MUST HAVE" accessory for your Big Dob. Roger builds 'em RIGHT!

    Obsession® Telescopes - by Dave Kriege - Heirloom Grade Telescopes for the discriminating astronomer



    Copyright 2003-2014, by Charles Starks, Charlotte, NC, All Rights Reserved

    Updated: 8:11 AM 12/16/2014