Tech Nerdery

Ben-tenna project 2.0

On Friday my MythTV server (my DVR software running on my server) had major audio and video artifacts and skipping during Dollhouse. This isn’t the first time this has happened and is particularly annoying since the TV upstairs rarely, if ever, has issues with Fox. Well, this was the last straw for me.

I know this was one of, or a combination of three possible issues.
1) Antenna is not good enough. It is a good antenna that I built, but not outdoor worthy, and where I have it in the house had to have multi-path issues.
2) Crappy tuner card. It is a cheap card and I know it isn’t the best tuner, but I didn’t want to shell out for a nice Hauppage or something similar. Anyone have any good Linux/MythTV compatible card recommendations that are under or around $80?
3) Hardware / hard drive issues. My server is an Athalon XP 1800 on an Asus A7V8X with a Seagate 300gb SATA with the recording partition formatted XFS. I’m a little worried that there are some I/O issues getting the data off the PCI card and onto the hard drive. Ideally at some point I would get a PCI express runner card on some dual-core (hopefully lower power when idling too – want to green this setup a bit w/ my P4 3.0 Ghz frontend PC).

So, I decided that tackling the antenna would give me the most bang for the buck long term (especially if I can get it permanently mounted on the roof or outside).

So, I was debating between a dual-bay version of the one I made previously (based on a Channel Master CM4221), or to go with this newer and GPL-licensed Gray-Hoverman. Did a little homework and decided on the Single Bay Gray-Hoverman despite it being slightly more complex to build well when compared to the dual bay channel-master style. So, did a little internet poking and found this site which documents a guy building his out of PVC.

I didn’t deviate too far from the original design plans for the active elements of the Gray-Hoverman, and copied his frame (only with a single-bay version) almost exactly.

It cost probably close to $50 by the time I bought a pipe cutter and a hack saw (how did I not have one of these before????), so the PVC and screws and washers probably came out to more like $20-$30, and then the copper wire wasn’t cheap, but I bought it a long time ago in anticipation for this project and don’t remember how much it was, and the chicken wire was laying around from our “de-mousing the vents project” a year ago.

Gallery should be attached below of some of the work-in-progress and completed builds. I have only tested it a little and it gets OK reception sitting on my couch. If I put it outside on the roof (that sounds like a PITA though, and I’m lazy) I bet it will do better than any of the old ones I built, and it will stand up to weather better (just needs some outdoor PVC paint first).

I’ll put mroe details about the performance for local channels after I get time to compare it to my older ones built out of cardboard, wood, and coat-hangers. I’m expecting good things, but those old ones didn’t suck. What will suck, is if this tuner on this HDTV card really does suck that bad, and this doesn’t help very much. (for reference I have a Kworld ATSC-155)

And finally, before the pics, some links for more interesting info:
Two articles about building the antenna from some RF magazine
And the PDF for the GPLv3 version of the antenna with the rod reflectors/passive elements.