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Originally Posted by WIRELESS ENGINEER

Yes you can easily make a 4 bay bowtie antenna that works better than any commercial 4 bay

The bowtie antenna is primarily a UHF-mostly design and usually has poor VHF performance. The only DIY 4-bay that I'd suggest investigating is the "M4" design which is well discussed in this thread over at DHC: http://www.digitalhome.ca/forum/186-...-featured.html This design features elements of a length and spacing pretty close to what WIRELESS ENGINEER suggested. This is an excellent design which was done by enthusiasts who were concentrating on performance, unfettered by concerns that must be present for a commercial design. Most of the You-tube coat hangers are based on a very poor design and should be avoided.

Since most commercial versions still have most of their gain above 700 MHz, (where no dtv stations exist) they perform poorly on the lower half of the UHF channels

I'll just note that our "e"-series of bowties, launched back in 2011, do not have this concern. They were designed specifically for the channel range of 14-51 and have only about a 2.5 dB gain differential from design band edge to design band edge. Data from other manufacturers regarding this performance is pretty much non-existent. Winegard discontinued their bowties several years ago without ever updating them. Channel Master redesigned their bowties back around the digital transition, but they publish a single gain number and then fail to even specify what what frequency it's at or which gain figure they're using, the just say "dB" which is not specific. The Chinese-made clones are typically of Euro-Asian specs and go up into the 860 MHz range (not optimized for North American UHF band).

I'll just say that I am not recommending our "e" series antennas for this location unless it is also paired with a suitable high-VHF antenna.

Sensar RV-2005

The Winegard Sensar, without the Wingman attachment, was designed decades ago and it's performance was concentrated in the channel 2-13 range. The clip-on Wingman was later added to offers a bit of UHF improvement. The built-in amp on older units was similar to the discontinued HDP-269 preamp. The Sensar is broadly bi-directional on VHF (hence the need to a rotating mechanism with their RV mounts).

ONN, model ONA16AV004 (believe that to be the model)

Ugh!

best reception facing NE (I would guess about 15 deg)

The expected aiming direction would indeed be almost due NE as per your plot.

Your best bet would likely be one of the medium-sized combo antennas (7-51 or 7-69) aimed at downtown Seattle. Note that any directional antenna aimed in this fashion would introduce the following concerns:

1. The primary transmitter for your Fox affiliate is located of to your northWEST. It's signal is quite strong so it probably will come in anyway. That station also operates a low-power UHF 22 transmitter from the downtown area, so there is a second opportunity to pick it up.

2. The PBS station in Tacoma, WBTC, will probably be lost as it's going to be in a significant null with any directional antenna. If this station is desired enough, you'd have to make special provisions for it.

3. You'll want to add a medium gain, high-input preamp to the system.