Bow Tie TV Antenna Designs (mclapp's M4 featured) - Page 71 - Canadian TV, Computing and Home Theatre Forums

mclapp · 2012-01-01, 05:07 PM

The vertical stack makes more gain because the elements are spread out further apart so the elements are not stealing as much signal from each other and you get a larger effective reflector area. Also the feeder that connects the 2 four bays is easier and cleaner to do on a vertical stack. The down side is they are larger area wise and have higher chance of multi-path compared to the horizontal stack. It's best to stick to no more than 4 bays to a common phase line and then co-phase the 4 bays together.

doubledot101 · 2012-01-04, 02:33 PM

Thanks for the info Mclapp.I currently have my M4 stacked horizontally and mounted to my chimmeny.I didn,t get a chance to mount the reflectors.When spring arrives I will continue the build.I,m still not sure if I will go vertically or continue the horizontal build.For now I get 18 to 22 channels depending on the weather.I,m okay with that till the spring.

JSA · 2012-01-05, 12:37 PM

Hi All,
I'm in the process of putting together material for an m4 (9.5 x 9) antenna. I've made the mast already out of 1" PVC, the standoffs are also 1" PVC glued and attached to the mast with through bolts and lock nuts. As for the whiskers, I've got 10 Awg wire. My question is about the wire for the phase lines. I have quite a bit of 14 Awg wire and would like to know if this is ok or if it must be *the same gauge as the whiskers?

BOUVAL · 2012-01-05, 12:57 PM

Quote:

I have quite a bit of 14 Awg wire and would like to know if this is ok or if it must be *the same gauge as the whiskers?

JSA,

14 AWG is fine, but not smaller than that. Make sure that there ain't much more than 1 1/4 inch between those phase lines.
.

JSA · 2012-01-09, 12:32 PM

Thanks Bouval! I have read through the previous posts and it has been suggested that the balun be mounted on the back of the mast away from the phase lines. Is it ok to extend the leads of the balun to wrap around to the balun standoff, or is this really necessary?

mclapp · 2012-01-09, 03:06 PM

The big thing is to try to stay away from running the feed line/balun in parallel with the near by phase lines.

Attach to the feed point then exit away as close to 90 deg as possible for a few inches before running the feedline in parallel behind the screen is safest to reduce any skewing of the wave caused by the feedline.

I'm sure other methods will work fine but that method will help insure no problems are being caused by the feedline/balun.

holl_ands · 2012-01-11, 03:36 PM

mclapp: Could you post (or add to website) the 4nec2 file used to make the fol. Vertical 8-Bay charts?
http://m4antenna.eastmasonvilleweath...dels%20M8.html

I have half-a-dozen of your old 8-Bay EZNEC files, but after conversion to 4nec2 they
have lots of Errors that need to be resolved and none of them have the same filename....

Thnx

mclapp · 2012-01-12, 09:49 PM

I'll see what I can find all my stuff was made in EZNEC so I don't know how any of them will transfer to 4NEC2, one of the ones you've already tried may be the one and that's all there is. I haven't messed with those models in a couple of years, you're right I have lots of small variations of that antenna messing with the co phase line, reflector spacings and shapes.

JSA · 2012-01-14, 10:55 PM

Hi All,
Finished building my 9.5x9 antenna and have it up in my attic and I can't begin to express how impressed I am. I live in Brampton Ontario which is approximately 30km (19miles) from the CN Tower in toronto. After inputting my coordinates into TVFool I pointed my antenna to approximately 124 degrees which would put me between toronto and the channels i hoped to receive from Buffalo. On first attempt with a cheap 10db Zenith amplifier, and bowes swept back about 1" and no reflector I am receiving 23 channels with the furthest being cbs (4.1) at 156kms away (96miles) and about 25 degrees off from where the antenna is aimed. Excellent design mclapp, thanks for giving the geek in me a huge smile and something to build upon!

BOUVAL · 2012-01-16, 12:52 PM

JSA,

I'd be curious if you'd put a reflector behind your antenna.

A good reflector made of thick cardboard covered with aluminum foil 5~6 inches behind the whiskers. It's size would be about 39 by 33 inches.

If you do so, it'd be nice to see your before and after reception with the real RF channel numbers.
.

morehp · 2012-01-16, 01:09 PM

JSA

the cbs station at 96 miles away is amazing considering you indicated the antenna is attic installed... is CBS constant or does it depend on the day?

which mclapp did you build?

JSA · 2012-01-17, 05:02 AM

Bouval,
As of this moment I hadn't considered a reflector since my reception results are surprisingly good. If I do I will definately post my results.

Morehp,
I built the 9.5x9 antenna. So far my install of only 4 days has had excellent and very consistent reception. I actually just turned my antenna a few more degrees east yesterday afternoon which gave me a little more strength on CBS and a whopping 20% increase (according to my Tv's signal meter) on NBC. And although the signal is too weak to view my tv now recognizes channel 26-1 and it's sub stations which it hadent before. For some reason though I've lost a little on CBC, but all other Toronto stations are still exceptionally strong.

HDTV Junkee · 2012-01-20, 07:34 PM

As I have done -- you may also build another "identical" antenna to be placed right next to your exising "homeade". Hook both up through a "splitter" (good quality) -- in reverse using two equal pieces of RG Cable.

I have placed cardboard with tin-foil approximately 5 inches behind the antennas for the extra power (use enough cardboard to cover the area behind both antennas). TV / Refrigerater boxes (old screens) etc.

NB: I actually use a 3-splitter with a separate antenna for TO stations / VHF powered. 29.1 is hit and miss since November.

Best wishes for the new year. And I echo your thoughts on the original Mclapp designs.

fireflimoon · 2012-01-21, 04:06 PM

Hi,

My mom is interested in getting PBS and Fox if possible and the tvfool for her is this: http://www.tvfool.com/?option=com_wr...67d90f14456e95

I am thinking of building a stacked M8 like this one http://m4antenna.eastmasonvilleweath...dels%20M8.html using 10awg copper.

I'd like to see if I could get PBS without a preamp first.

Would this be the right model to give it a try or is there a better one more suited to her site?

Thanks

be236 · 2012-01-21, 04:22 PM

Well, I bought an HD-8800 and its performance is similar to my M4 (10.5 x 10") design.

However, strangely enough the HD-8800 gets a signal sniff (but no picture lock) on higher UHF (RF 32 and 43 and 47) that my M4 rarely sees. Target stations are 107 miles away and 2EDGE and NMs -8 to -15dB.

Alas, not sure what my next move is... to build another M4 to make and M8... or get a Yagi, like CM 3023, HD -9032 or 91XG....

hmm...

2012-01-05, 12:37 PM	#1053
JSA Join Date: Oct 2007 Location: Brampton, Ontario Posts: 62	M4 antenna project Hi All, I'm in the process of putting together material for an m4 (9.5 x 9) antenna. I've made the mast already out of 1" PVC, the standoffs are also 1" PVC glued and attached to the mast with through bolts and lock nuts. As for the whiskers, I've got 10 Awg wire. My question is about the wire for the phase lines. I have quite a bit of 14 Awg wire and would like to know if this is ok or if it must be *the same gauge as the whiskers?

2012-01-14, 10:55 PM	#1059
JSA Join Date: Oct 2007 Location: Brampton, Ontario Posts: 62	Mclapps amazing antenna! Hi All, Finished building my 9.5x9 antenna and have it up in my attic and I can't begin to express how impressed I am. I live in Brampton Ontario which is approximately 30km (19miles) from the CN Tower in toronto. After inputting my coordinates into TVFool I pointed my antenna to approximately 124 degrees which would put me between toronto and the channels i hoped to receive from Buffalo. On first attempt with a cheap 10db Zenith amplifier, and bowes swept back about 1" and no reflector I am receiving 23 channels with the furthest being cbs (4.1) at 156kms away (96miles) and about 25 degrees off from where the antenna is aimed. Excellent design mclapp, thanks for giving the geek in me a huge smile and something to build upon!

2012-01-16, 12:52 PM	#1060
BOUVAL Join Date: May 2011 Location: Vimont, Laval, Qc. Posts: 611	M4 reception JSA, I'd be curious if you'd put a reflector behind your antenna. A good reflector made of thick cardboard covered with aluminum foil 5~6 inches behind the whiskers. It's size would be about 39 by 33 inches. If you do so, it'd be nice to see your before and after reception with the real RF channel numbers. . __________________ Mes photos: http://s1140.photobucket.com/albums/n574/BOUVAL-OTA/

2012-01-21, 04:22 PM	#1065
be236 Join Date: Sep 2011 Location: Everett, WA Posts: 406	Well, I bought an HD-8800 and its performance is similar to my M4 (10.5 x 10") design. However, strangely enough the HD-8800 gets a signal sniff (but no picture lock) on higher UHF (RF 32 and 43 and 47) that my M4 rarely sees. Target stations are 107 miles away and 2EDGE and NMs -8 to -15dB. Alas, not sure what my next move is... to build another M4 to make and M8... or get a Yagi, like CM 3023, HD -9032 or 91XG.... hmm... __________________ My Tvfool: http://www.tvfool.com/?option=com_wr...2df982d3f2a9b0

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

2012-01-01, 05:07 PM	#1051
mclapp Join Date: Aug 2008 Location: Upstate NY Posts: 597	The vertical stack makes more gain because the elements are spread out further apart so the elements are not stealing as much signal from each other and you get a larger effective reflector area. Also the feeder that connects the 2 four bays is easier and cleaner to do on a vertical stack. The down side is they are larger area wise and have higher chance of multi-path compared to the horizontal stack. It's best to stick to no more than 4 bays to a common phase line and then co-phase the 4 bays together.

2012-01-04, 02:33 PM	#1052
doubledot101 Join Date: Apr 2011 Location: Burlington,Ont Posts: 33	Thanks for the info Mclapp.I currently have my M4 stacked horizontally and mounted to my chimmeny.I didn,t get a chance to mount the reflectors.When spring arrives I will continue the build.I,m still not sure if I will go vertically or continue the horizontal build.For now I get 18 to 22 channels depending on the weather.I,m okay with that till the spring.

2012-01-09, 12:32 PM	#1055
JSA Join Date: Oct 2007 Location: Brampton, Ontario Posts: 62	Thanks Bouval! I have read through the previous posts and it has been suggested that the balun be mounted on the back of the mast away from the phase lines. Is it ok to extend the leads of the balun to wrap around to the balun standoff, or is this really necessary?

2012-01-09, 03:06 PM	#1056
mclapp Join Date: Aug 2008 Location: Upstate NY Posts: 597	The big thing is to try to stay away from running the feed line/balun in parallel with the near by phase lines. Attach to the feed point then exit away as close to 90 deg as possible for a few inches before running the feedline in parallel behind the screen is safest to reduce any skewing of the wave caused by the feedline. I'm sure other methods will work fine but that method will help insure no problems are being caused by the feedline/balun.

2012-01-11, 03:36 PM	#1057
holl_ands Veteran Join Date: Nov 2008 Location: San Diego, CA Posts: 1,606	mclapp: Could you post (or add to website) the 4nec2 file used to make the fol. Vertical 8-Bay charts? http://m4antenna.eastmasonvilleweath...dels%20M8.html I have half-a-dozen of your old 8-Bay EZNEC files, but after conversion to 4nec2 they have lots of Errors that need to be resolved and none of them have the same filename.... Thnx

2012-01-12, 09:49 PM	#1058
mclapp Join Date: Aug 2008 Location: Upstate NY Posts: 597	I'll see what I can find all my stuff was made in EZNEC so I don't know how any of them will transfer to 4NEC2, one of the ones you've already tried may be the one and that's all there is. I haven't messed with those models in a couple of years, you're right I have lots of small variations of that antenna messing with the co phase line, reflector spacings and shapes.

2012-01-16, 01:09 PM	#1061
morehp Join Date: Jul 2009 Location: North end of Lake Simcoe (Val Harbour on Barnstable Bay) Posts: 103	JSA the cbs station at 96 miles away is amazing considering you indicated the antenna is attic installed... is CBS constant or does it depend on the day? which mclapp did you build?

2012-01-17, 05:02 AM	#1062
JSA Join Date: Oct 2007 Location: Brampton, Ontario Posts: 62	Bouval, As of this moment I hadn't considered a reflector since my reception results are surprisingly good. If I do I will definately post my results. Morehp, I built the 9.5x9 antenna. So far my install of only 4 days has had excellent and very consistent reception. I actually just turned my antenna a few more degrees east yesterday afternoon which gave me a little more strength on CBS and a whopping 20% increase (according to my Tv's signal meter) on NBC. And although the signal is too weak to view my tv now recognizes channel 26-1 and it's sub stations which it hadent before. For some reason though I've lost a little on CBC, but all other Toronto stations are still exceptionally strong.

2012-01-20, 07:34 PM	#1063
HDTV Junkee Join Date: Apr 2011 Posts: 174	As I have done -- you may also build another "identical" antenna to be placed right next to your exising "homeade". Hook both up through a "splitter" (good quality) -- in reverse using two equal pieces of RG Cable. I have placed cardboard with tin-foil approximately 5 inches behind the antennas for the extra power (use enough cardboard to cover the area behind both antennas). TV / Refrigerater boxes (old screens) etc. NB: I actually use a 3-splitter with a separate antenna for TO stations / VHF powered. 29.1 is hit and miss since November. Best wishes for the new year. And I echo your thoughts on the original Mclapp designs.

2012-01-21, 04:06 PM	#1064
fireflimoon Join Date: Nov 2011 Posts: 155	Hi, My mom is interested in getting PBS and Fox if possible and the tvfool for her is this: http://www.tvfool.com/?option=com_wr...67d90f14456e95 I am thinking of building a stacked M8 like this one http://m4antenna.eastmasonvilleweath...dels%20M8.html using 10awg copper. I'd like to see if I could get PBS without a preamp first. Would this be the right model to give it a try or is there a better one more suited to her site? Thanks