W8BI Amateur Television Group

Getting Started in ATV

Contact info:  Jesse Nicely, KB8OFF, DARA ATV Group Chairman, kb8off@arrl.org

Adam MacDonald, N1GX, calvinf15@earthlink.net, (937) 320-1085

1.  Web Resources (in no particular order…)

            - www.w8bi.org  Click on “W8BI ATV Group” under LINKS

            - http://psycho.psy.ohio-state.edu/atco  Art Towslee’s (WA8RMC) Columbus ATV group.

- http://atv-tv.org  Big link page describing the majority of the larger ATV groups.

-  www.qsl.net/atn/ATN.htm  Home page of the large Amateur Television Network that spans Southern CA, Nevada, Arizona New Mexico, Indiana and soon Illinois.

- www.hamtv.com  Tom O’Hara’s PC Electronics ATV equipment manufacturer. Good source for application notes specific to ATV.  One of the few sources of turnkey ATV transmitter and receiver equipment

- www.tvham.com  Mr. Giles G1MFG in the UK distributes FM ATV transmitter and receiver modules.  Note that these modules are available elsewhere, for example,

- www.ebay.com  Search for seller ID “gnupic”.  This gentleman lives in the Netherlands and has very reasonable shipping to the USA for his FM ATV devices.   Note that these boards are constructed using the same FM TX/RX modules made by Comtec that G1MFG imports from Taiwan.  He also has a web store at www.mobicomm.com/store .  Although he only lists 2.4 GHz on his store, we have seen his 1.2 GHz boards on Ebay.

- http://www.qsl.net/wk8l/  Good info describing the construction of slot antennas.

- http://www.si-list.org/swindex2.html  Unofficial NEC (numerical electromagnetic code) website.  Scroll down to 4NEC2 and download.  This is an excellent (free!) graphical program that allows accurate modeling of antennas.  Lots of other good code on this site as well.

- www.sbszoo.com/ve6sbs  Barry has some very nice information regarding mods to the G1MFG FM boards for use with ATV.  Warm up that soldering iron!

- www.danalee.ca/ttt  A very nicely done page by Dana M Lee that describes many of the technical aspects of television.

- www.videouniversity.com/tvbars2.htm  Excellent description of NTSC colorbars and their application to improving and monitoring the quality of your TV signal.

-  www.ussc.com/~uarc/utah_atv/psandqs.html  Paper describing the (somewhat subjective) P-rating (picture rating) system used by ATVers.

2.  Local Repeater Group and ATV Site information

- ATV Net:  Wednesday night at 2100L (9:00 PM) check-in on 144.34 simplex.

- ATV Repeater Inputs: 439.25 MHz VSB (reversed, lower VSB), 1258 MHz FM.

- ATV Repeater Outputs: 421.25 MHz VSB (normal, upper VSB), 1258 MHz FM.

- All antenna are horizontally polarized.

- ATV Repeater Location/Details: Beyer’s Road 39 degrees 37.209 minutes (latitude) 84 degrees 14.218 minutes  (longitude).995 feet above sea level, 165 foot tower.  Total height MSL is approx 1150 feet

3.Ongoing and Future group projects (please contact KB8OFF or N1GX to get involved)

- Completion and enhancement of the DARA / ATCO audio-video link. Additional work needed to construct a remotely controlled camera and other improvements to this link.

- 421.25 MHz Transmitter improvement project. Know of a good deal on a high-powered linear amplifier that would cover the 420-430 MHz band?Most available amplifiers are designed for saturated operation suitable for FM, but not for AM or VSB video transmission.Right now we have our eye on purchasing the Teletec DXP-U150, but we are open to other options. The Mirage just isn’t cutting it.

- Blockhouse upgrade.  Can’t solder to save your life?  Use your skills in helping us brighten the DARA ATV blockhouse.  One sunny day this Spring, we plan to buy a few gallons of exterior paint and give the blockhouse that polished, professional look.  This is a great chance to meet the ATVers in person and get out on a rare sunny day in Dayton.  We will also be attempting to repair some small roof leaks that have plagued us during these past wet months.  Date/time/directions TBA in the RF carrier.

- ATV over IP.  This is an exciting project and promises to push the Dayton ATV group into the national spotlight by introducing an important enabling technology.  Are you a computer wiz?  Have you ever looked into the video-over-internet tools built into Windows or Linux?  Can you program in C or some other mainstream language?  If so, we love to hear your ideas on launching this novel technology.  This project is still in the “pipe-dream” stage, so any input you make will have tremendous impact at getting this off the ground.

- Digital ATV. Have a look on the web for related technology.  Commercial off-the-shelf equipment exists.  Some set-top satellite receiver boxes would make perfect digital ATV receivers. The big broadcast guys are doing it. Hey, Columbus (ATCO) is even doing it!The benefits range from better stewardship of your ham bands to increased transmission range with unprecedented picture quality. With the ASIC chipsets manufactured for todays digital picture phones, it’s not too much of a reach to imagine a network where the

-DARA ATV repeater serves mobile ATVers and even personal handheld, low power video tranceivers with important info such as weather and event information. It’s the next level of amateur communication. Imaging this level of connectivity when coupled with ATVoIP discussed above! You’d be communicating with ham buddies in Toledo using video, mobile!

-ATV is an exciting and accessible facet of amateur radio that provides virtually unlimited potential for those who want to increase their technical skills, and benefit the greater Dayton amateur radio community.  There is really something to seeing the hams you are working, in full color live video.  Even ATV DX is possible when the conditions are right (OK, our definition of DX is a bit limited, but 100 miles or more is possible with good tropo-ducting).  We’d love to see you on the Wed evening net, and look forward to any participation, no matter how small.  Get bitten by the ATV bug!

Powerpoint Presentation download pdf file (3.0 Mb for dsl or broadband)

Presented at the DARA general meeting on March 4, 2005