Seeking outdoor antenna advice, SF Bay Area

tgreene

DTVUSA Jr. Member
#1
I live in unincorporated San Mateo County on the San Francisco peninsula within about 25 miles of the towers broadcasting the channels I'm interested in, but a number of them are blocked by hills and not LOS. TV Fool report here: TV Fool

I am currently using a full size "HD Frequency Cable Cutter" indoor antenna (Best Indoor HDTV Antennas - Cable Cutter) . It is about 12' off the ground in a window facing NW, and it is connected to the TV with a new 40' RG6 coax cable of good quality. It works pretty well on the channels I want during the day, but I fall off the 'digital cliff' and lose many channels at night.

I'd very much appreciate recommendations for an outdoor antenna that will be able to receive most of the stations that are above -70 dB in signal strength and are located between 327 to 90 degrees in angle on my TV Fool report. I'm OK with not getting the weaker stations (below -70 dB), and I'm most interested in Channel 7 and up (OK to not get lower ones).

I have an old satellite dish (Dish or Direct TV) on my roof that has an older but seemingly OK dual coax cable running from it to under my house and eventually to the TV (maybe 100 - 120' total). An oak tree about 40' away partially blocks the antenna location to the N (NW and E are OK). I did try my indoor antenna in that location with the existing cable and did not notice improvement in the daytime over its nominal indoor location (got many of the same channels as inside after messing with its location). Would it be OK if I used this existing cable, and would I need an amplifier given its length?

Thanks very much in advance for any suggestions on the antenna and cable!

Cheers,

TG
 
#2
Your signal levels are certainly predicted to be high enough too receive all major networks from the 330 direction, if the tree does not block too much. You will need an antenna with both High VHF, and UHF capability. The first two antennas that come to mind for your situation.
Stellar Labs VHF/UHF HDTV 60 Mile Fringe Yagi Antenna | 30-2440 (302440) | Stellar Labs
OPEN BOX ITEM - AntennaCraft 33 Element UHF / High-Band VHF Outdoor HDTV Antenna (HBU33) from Solid Signal
I like the fact that you have already done some testing, and have provided us with some good information to start with. The left over coax should work fine. I always recommend removing any left over inline hardware replacing it with simple straight through barrel connectors.
Amazon.com: GE 23203 Cable Extension Adaptor Connects Two Coaxial Video Cables: Electronics
A thought I had on night time signal loss is the possibility of interference from lighting, or other house hold appliances. Some, but not all CFL lights are of very poor design that emit large amounts of radio frequency interference. This is more likely to effect VHF channels.
I think trying your current antenna out side was a very good idea. Is it built to withstand outdoor use? I've seen photos of that antenna mounted outside. If house hold noise is part of your problem with night time reception getting the antenna out side might help.
With over 100' of coax a pre-amp could help. I would try first with out it.
While I find the antenna you have to be of an interesting design. I wouldn't have volunteered my money to test it.
Steve
 

MrPogi

Moderator, , Webmaster of Cache Free TV
Staff member
#3
It's going to be difficult to get all those channels, both UHF and VHF, spread from NW to E with a single antenna. There may be a 2 antenna solution or you may end up having to get a rotor.
 

tgreene

DTVUSA Jr. Member
#4
Thanks for the great info RF Steve and MrPogi - on Thanksgiving, no less!

The day/night issue seems to be atmospheric; I've experimented with turning lights (CFLs) on and off and see no difference, and wifi is on at all times. I was also concerned about getting over 90 degree coverage with a single antenna, but it looks like the LOS stations in the E need less gain than the ones in the NW, so maybe I can get both with the antenna oriented a bit E of N.

I very much appreciate RF Steve's specific recommendations. However, I couldn't find plot of either antenna's sensitivity as a function of angle. Is there a database somewhere? Also, is there a standard diameter of the masts that come with these antenna? I'm trying to figure out the mounting.

Lastly, does anybody have any comments on this Antennas DIrect VHF/UHF antenna: https://www.antennasdirect.com/stor...HF-Long-Range-Indoor-Outdoor-DTV-Antenna.html ? I like that it is compact, and its specs include a sensitvity pattern that I may be able to live with.

TomG
 
#5
Antennacraft's statement on directivity is expressed as half power beamwidth, and front to back ratio. Antennacraft's gain statement is in dB over a half wave dipole. Add 2.15 dB to get dBi. Antennas Direct states gain in dBi. I feel Antennacraft is conservative with their gain claims.
http://www.antennacraft.net/pdfs/HBU33_.pdf
In my opinion the Stellar Labs gain claims are exaggerated. On some models they have backed off from the original inflated numbers. This subject has been discussed on this forum in the past.
http://www.mcmelectronics.com/content/ProductData/Spec Sheets/30-2440.pdf
Even if one took the lower gain numbers as 7 dBi VHF and 10 dBi UHF that is still a very respectable little dual band antenna.
The ClearSteam 2V is a very good little dual band antenna the main advantage of the ClearStream antenna is the 70 degree horizontal half power beamwidth while still producing 10.2 dBi peak gain on UHF. The antenna is lacking in VHF gain with it's simple dipole for VHF, but may still prove to be enough. Antennas Direct seems to have backed off on the multi-directionl claims.
Took my first approach trying for as many stations in the 330 as possible. MrPogi is right it might not be possible with out two antenna to receive both direction with out a rotor or two antenna system.
Steve
 
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tgreene

DTVUSA Jr. Member
#6
I think that I've got my antenna setup dialed in pretty well now, and I'd like to thank RF Steve, MrPogi, and the whole forum for your crucial help.

I ended up going with the Antennas Direct Clearstream 2V on my roof for a few reasons:
1. Small, stiff, and light, making it compatible with the somewhat high mast required for using my existing satellite dish pipe mount.
2. Not as directional as the AntennaCraft HBU33; better chance of getting towers at ~327d to 87d.
3. I could buy it 3 mi from my house easy to return w/o shipping if needed.

The good news is that I can get all the stations I want, even Channel 12 (VHF HI) from a tower that is pretty heavily shadowed by the hills near me on the San Francisco Peninsula. I had to orient the antenna through a gap in the hills close to (about 10 deg from) the direction of the obscured Mt San Bruno and Sutro towers for best signal. I was able to do this using the existing >10 yr old coax on my roof from an old satellite dish with a length of over 100' to my TV. There is a single inline coupler (no splitters or other hardware), and I'm pleased that I didn't need a preamp (not yet at least...).

I can now get a much wider variety of local broadcast stations that my old cable provider (Comcast) offered, at better quality too.
I'm on happy camper, thanks to you!

Cheers,

Tom
 
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