Stacking, Ganging, Combining TV Antennas - Page 51 - Canadian TV, Computing and Home Theatre Forums

ProjectSHO89 · 2012-03-02, 05:39 PM

Keep in mind that a channel 13 Jointenna will have its roll-off in channel 12. If your tuner can handle it, you're fine.

balm · 2012-03-03, 09:46 AM

So if I put a VHF-Hi yagi (For #10, #12, #13) on a rotor, how far above the CM4228HD on the 3 ft tripod, do I need to go, if its even possible (structurally) ...the 2 antennas will be combined.

thanks

envirogeek · 2012-03-03, 01:00 PM

I am considering planting a mast on the peak of my roof to relocate my existing AntennaCraft U8000 8bay antenna, then also attach a CPE from a wireless internet provider on the top of the same mast.

If I use a tripod, 10 foot mast, 5 feet of mast above the tripod, this would put the CPE approximately 1.5 to 2 feet above the top of the 8 bay antenna.

I should have no more than 15-20 pounds of devices on the mast with the antenna and CPE, and I may add a preamp. The TV antenna will be aimed approximately 48 degrees true (across the most common prevailing winds) and the CPE approximately 286 degrees (facing the prevailing winds).

I believe this should be a sufficiently stable mounting for the weight of equipment, but I am not sure if I should be concerned about potential interference between the two antennas.

I am wondering if anyone sees any concerns based on the conditions I have presented?

Thanks in advance.

holl_ands · 2012-03-03, 01:02 PM

At least 4-ft separation measured from Yagi to nearest metal in CM4228HD
in order to NOT degrade the F/B Ratio. Gain is much more tolerant:
http://imageevent.com/holl_ands/stacked

goforit · 2012-03-03, 01:23 PM

What about optimal stacking distance for a 91XG (top) and a Winegard VHF-Hi 1713?

goforit · 2012-03-04, 12:14 PM

Okay, I found the answer- 26 inches or more.

fireflimoon · 2012-03-06, 08:06 AM

Hi,

Was wondering what I would need to do to combine a VHF-HI with a SBGH already in the attic that is receiving ch 13. Even though the SBGH is receiving the signal, at times the signal is low (still watchable but a few blocky patches). It is mostly fine though.

For a comparison to see if my build is good I might build a second one later and try to stack the gh4n3 with another one (to increase VHF-HI and also for fun but also to try it at another location further away).

For now, if I build a different VHF-HI antenna and join it to the UHF signals from the SBGH using a UVSJ, do I need to take care with the length of the feedline coax going from the baluns of each antenna to the UVSJ? Do they have to be the same length? Is there anything basic that I should do regarding this?

I was thinking of making a coac balun for the VHF-HI antenna to optimize it for that signal range so any thoughts on that would be great...

Thanks

roger1818 · 2012-03-06, 09:08 AM

No, you don't need to worry about cable lengths or balun polarity when combining VHF and UHF antennas. This is only necessary when combining identical antennas pointed in the same direction (and the antennas are pointed towards the transmitter) with a broadband combiner. If any of those are not true, the phase of the signal will not be the same coming out of the antennas, so there is no need to try and match phases.

fireflimoon · 2012-03-06, 03:13 PM

Roger1818,

Thanks - hey btw would you identify combiners you have used and liked?

holl_ands · 2012-03-06, 03:35 PM

See combiner tests at www.antennahacks.com. Since back-to-back tests, divide Loss by 2.

roger1818 · 2012-03-06, 03:50 PM

fireflimoon, many pre-amps have separate VHF and UHF inputs, so that is a good option. If not, the most common one is the Pico Macom (TruSpec) UVSJ.

golfgirl · 2012-03-10, 01:13 PM

Hi, we have a channel master 4228HD installed and was just given an antennacraft 5884 Color King VHF UHF FM TV Antenna (5884). Is it possible to combine these two antennas for better reception? thanks in advance

poutanen · 2012-03-10, 03:40 PM

Generally speaking, combining non identical antennas will result in lower reception instead of better (do to the 3 db combiner loss). Even combining identical antennas only works well when the spacing is correct, phasing is correct, equal length coax, etc. etc.

Best bet is to have one optimum antenna for a given channel you're trying to get in a certain direction.

I've never used that particular antenna, but it looks like the 4228 has a much higher gain in the UHF band, so you're probably better of sticking with the 4228 alone. If you also have VHF signals you want to get in your area, by all means stack them and run the 4228 into the UHF input on a pre-amp, and the colourking into the VHF...

majortom · 2012-03-10, 04:47 PM

or as roger said in post 761 above, insert uvsj in place of preamp....run the 4228 into the UHF input on a UVSJ, and the colorking into the VHF...

balm · 2012-03-12, 03:12 PM

Any ideas on how to join a CM4228HD with an FM omni antenna. The CM4228HD will be recieving VHF-HI channels also off its side.

Can I join these, if so, whats used to join them, and how far apart do they need to be... if not I assume I need to run 2 separate cables for each.. ?

Also is there a recommended store-bought FM antenna for this?

Thanks

2012-03-03, 09:46 AM	#752
balm Veteran Join Date: Jan 2009 Location: Montreal Posts: 2,248	rotor So if I put a VHF-Hi yagi (For #10, #12, #13) on a rotor, how far above the CM4228HD on the 3 ft tripod, do I need to go, if its even possible (structurally) ...the 2 antennas will be combined. thanks

2012-03-03, 01:00 PM	#753
envirogeek Join Date: Mar 2006 Location: Calgary - Shaw phone & internet, 4 bay OTA in attic / Pigeon Lake - CCI Wireless, 8 bay OTA on roof Posts: 536	Stacking 8 Bay and 802.16 WISP CPE? I am considering planting a mast on the peak of my roof to relocate my existing AntennaCraft U8000 8bay antenna, then also attach a CPE from a wireless internet provider on the top of the same mast. If I use a tripod, 10 foot mast, 5 feet of mast above the tripod, this would put the CPE approximately 1.5 to 2 feet above the top of the 8 bay antenna. I should have no more than 15-20 pounds of devices on the mast with the antenna and CPE, and I may add a preamp. The TV antenna will be aimed approximately 48 degrees true (across the most common prevailing winds) and the CPE approximately 286 degrees (facing the prevailing winds). I believe this should be a sufficiently stable mounting for the weight of equipment, but I am not sure if I should be concerned about potential interference between the two antennas. I am wondering if anyone sees any concerns based on the conditions I have presented? Thanks in advance.

2012-03-03, 01:23 PM	#755
goforit Join Date: Sep 2008 Location: Hamilton Mtn. Posts: 1,454	What about optimal stacking distance for a 91XG (top) and a Winegard VHF-Hi 1713? __________________ 91XG, C5, CPA-19; Denon AVR-1312

2012-03-04, 12:14 PM	#756
goforit Join Date: Sep 2008 Location: Hamilton Mtn. Posts: 1,454	Okay, I found the answer- 26 inches or more. __________________ 91XG, C5, CPA-19; Denon AVR-1312

2012-03-06, 08:06 AM	#757
fireflimoon Join Date: Nov 2011 Posts: 155	UVSJ for SBGH and other antenna for VHF-HI comparison Hi, Was wondering what I would need to do to combine a VHF-HI with a SBGH already in the attic that is receiving ch 13. Even though the SBGH is receiving the signal, at times the signal is low (still watchable but a few blocky patches). It is mostly fine though. For a comparison to see if my build is good I might build a second one later and try to stack the gh4n3 with another one (to increase VHF-HI and also for fun but also to try it at another location further away). For now, if I build a different VHF-HI antenna and join it to the UHF signals from the SBGH using a UVSJ, do I need to take care with the length of the feedline coax going from the baluns of each antenna to the UVSJ? Do they have to be the same length? Is there anything basic that I should do regarding this? I was thinking of making a coac balun for the VHF-HI antenna to optimize it for that signal range so any thoughts on that would be great... Thanks

2012-03-02, 05:39 PM	#751
ProjectSHO89 Join Date: Nov 2009 Posts: 299	Keep in mind that a channel 13 Jointenna will have its roll-off in channel 12. If your tuner can handle it, you're fine.

2012-03-03, 01:02 PM	#754
holl_ands Veteran Join Date: Nov 2008 Location: San Diego, CA Posts: 1,606	At least 4-ft separation measured from Yagi to nearest metal in CM4228HD in order to NOT degrade the F/B Ratio. Gain is much more tolerant: http://imageevent.com/holl_ands/stacked

2012-03-06, 09:08 AM	#758
roger1818 Veteran Join Date: Apr 2006 Location: Ottawa (Stittsville), ON, OTA (Radio Shack Omnidirectional Antenna and 5Y6S in Attic), MythTV HTPC Posts: 5,630	No, you don't need to worry about cable lengths or balun polarity when combining VHF and UHF antennas. This is only necessary when combining identical antennas pointed in the same direction (and the antennas are pointed towards the transmitter) with a broadband combiner. If any of those are not true, the phase of the signal will not be the same coming out of the antennas, so there is no need to try and match phases. __________________ Link to my TVFool results is in my profile Homepage URL. I suggest others do the same.

2012-03-06, 03:13 PM	#759
fireflimoon Join Date: Nov 2011 Posts: 155	Roger1818, Thanks - hey btw would you identify combiners you have used and liked?

2012-03-06, 03:35 PM	#760
holl_ands Veteran Join Date: Nov 2008 Location: San Diego, CA Posts: 1,606	See combiner tests at www.antennahacks.com. Since back-to-back tests, divide Loss by 2.

2012-03-06, 03:50 PM	#761
roger1818 Veteran Join Date: Apr 2006 Location: Ottawa (Stittsville), ON, OTA (Radio Shack Omnidirectional Antenna and 5Y6S in Attic), MythTV HTPC Posts: 5,630	fireflimoon, many pre-amps have separate VHF and UHF inputs, so that is a good option. If not, the most common one is the Pico Macom (TruSpec) UVSJ. __________________ Link to my TVFool results is in my profile Homepage URL. I suggest others do the same.

2012-03-10, 01:13 PM	#762
golfgirl Rookie Join Date: Jun 2011 Location: Lefroy, Innisfil Posts: 13	combining help Hi, we have a channel master 4228HD installed and was just given an antennacraft 5884 Color King VHF UHF FM TV Antenna (5884). Is it possible to combine these two antennas for better reception? thanks in advance

2012-03-10, 03:40 PM	#763
poutanen Join Date: Mar 2009 Location: Calgary Posts: 220	Generally speaking, combining non identical antennas will result in lower reception instead of better (do to the 3 db combiner loss). Even combining identical antennas only works well when the spacing is correct, phasing is correct, equal length coax, etc. etc. Best bet is to have one optimum antenna for a given channel you're trying to get in a certain direction. I've never used that particular antenna, but it looks like the 4228 has a much higher gain in the UHF band, so you're probably better of sticking with the 4228 alone. If you also have VHF signals you want to get in your area, by all means stack them and run the 4228 into the UHF input on a pre-amp, and the colourking into the VHF...

2012-03-10, 04:47 PM	#764
majortom Veteran Join Date: Jan 2009 Posts: 2,567	or as roger said in post 761 above, insert uvsj in place of preamp....run the 4228 into the UHF input on a UVSJ, and the colorking into the VHF... __________________ uhf/vhf combo rotor chimney mount homebrew vhf hi hpf ap-8700 preamp 4way split lg lcd dtt901 pctuner mythtv

2012-03-12, 03:12 PM	#765
balm Veteran Join Date: Jan 2009 Location: Montreal Posts: 2,248	FM Any ideas on how to join a CM4228HD with an FM omni antenna. The CM4228HD will be recieving VHF-HI channels also off its side. Can I join these, if so, whats used to join them, and how far apart do they need to be... if not I assume I need to run 2 separate cables for each.. ? Also is there a recommended store-bought FM antenna for this? Thanks

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