Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
Gary Schafer wrote: Measured on their range-they used to be based in Cleveland, and my father was one of the designers. (anybody here remember the PRO-27JR 27Mhz antenna? Or the original 4BTV?) -- Jim Barbour WD8CHL With all due respect to your father Jim, I think that 4 db of gain is wishful thinking. A 5/8 wave length antenna theoretically is a little over 3 db and in real life 3 db is seldom realized. If I am not mistaken a .64 wavelength would have at most a tenth of a db advantage over a 5/8 antenna. 73 Gary K4FMX Yeah-right-ok... -- Jim Barbour WD8CHL
Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
Jeff DePolo wrote: There are a lot of unknown variables here, including, but not limited to the size of the ground plane the antennas were mounted on, their heights above the ground plane, the method of coupling to the ground plane (direct, mag mount, etc.), matching networks' efficiencies, etc.. And more importantly, was the 4 dB gain a peak value, or at 0 degrees elevation? Typically a 5/8 wave over a perfect ground plane should be a little more than 3 dB better than a 1/4 wave on the horizon, but with so many unknowns and so much variability in mobile installations, there doesn't seem to be a definitive conclusion to be drawn here. Maybe Jim can provide more detail. --- Jeff Yes...this was actually mounted dead center in the roof of a car (remember this was around 1966-68, the car was a 65 or 66 Impala-BIG roof) and measurements were taken and at the same height as the antenna. I don't remember the distance from the car however, probably at least 30', maybe as much as 100'. Oh, and 'mag mounts' didn't really exist much then...you either mounted the antenna in a hole, or you didn't have an antenna. -- Jim Barbour WD8CHL
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
Oh, and 'mag mounts' didn't really exist much then...you either mounted the antenna in a hole, or you didn't have an antenna. Ah, the gold old days, when men armed with a drill and Greenlee punch thought nothing of putting holes in their roofs, fearing not the Wrath of Wife.
Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
Jeff DePolo wrote: Oh, and 'mag mounts' didn't really exist much then...you either mounted the antenna in a hole, or you didn't have an antenna. Ah, the gold old days, when men armed with a drill and Greenlee punch thought nothing of putting holes in their roofs, fearing not the Wrath of Wife. ROFL! -- Jim Barbour WD8CHL
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
At 07:29 AM 2/20/2007, you wrote: Ah, the gold old days, when men armed with a drill and Greenlee punch thought nothing of putting holes in their roofs, fearing not the Wrath of Wife. ---When I bought my new Mustang last year, within 24 hours of bringing it home, I installed a genuine NMO mount in the trunk lid. Of course, I've always sworn by using Greenlee punches for the hole too (none of those stepped drill bits for me!) My wife didn't even question me, other than what took you so long? Ken -- President and CTO - Arcom Communications Makers of the world famous RC210 Repeater Controller and accessories. http://www.arcomcontrollers.com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
Hello, Anyone remember Ed Juge? I worked for him back when he had his electronics shop on the South Freeway in Fort Worth. His wife got a new car, a little Porsche 911 and she wanted a Ham radio installed so she could use the local .94/10-4 repeater, Ed knew better than to try and install it on the roof. As a joke, he took a Larson gain antenna and set it on top of the car's roof while calling her to come see his handywork. Jo walked in, you could hear the scream all over the building! The customers were wondering what was happening! Sorry for the off-topic story but seemed appropriate! Paul -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Ken Arck Sent: Tuesday, February 20, 2007 9:42 AM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur At 07:29 AM 2/20/2007, you wrote: Ah, the gold old days, when men armed with a drill and Greenlee punch thought nothing of putting holes in their roofs, fearing not the Wrath of Wife. ---When I bought my new Mustang last year, within 24 hours of bringing it home, I installed a genuine NMO mount in the trunk lid. Of course, I've always sworn by using Greenlee punches for the hole too (none of those stepped drill bits for me!) My wife didn't even question me, other than what took you so long? Ken -- President and CTO - Arcom Communications Makers of the world famous RC210 Repeater Controller and accessories. http://www.arcomcontrollers.com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net Yahoo! Groups Links -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.441 / Virus Database: 268.18.3/693 - Release Date: 2/19/2007 5:01 PM -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.441 / Virus Database: 268.18.3/693 - Release Date: 2/19/2007 5:01 PM p class=style1Visit a href=http://www.ourphonelist.com;OurPhonelist.combrIt's free and you'll never lose track of a phone number again! /a/p Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) * To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Antennas that work both in commercial and amateur (war stories)
A number of years ago... an installer I knew drilled a cell phone mount into the transmission hump of a Jag... caught the Jag's wire harness and shorted/burned the entire car out when he hit the key. T'was a $4,000 + cost dealer fix... cheers, skipp Paul Finch [EMAIL PROTECTED] wrote: Hello, Anyone remember Ed Juge? I worked for him back when he had his electronics shop on the South Freeway in Fort Worth. His wife got a new car, a little Porsche 911 and she wanted a Ham radio installed so she could use the local .94/10-4 repeater, Ed knew better than to try and install it on the roof. As a joke, he took a Larson gain antenna and set it on top of the car's roof while calling her to come see his handywork. Jo walked in, you could hear the scream all over the building! The customers were wondering what was happening! Sorry for the off-topic story but seemed appropriate! Paul
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
Ken, I, too, used a Greenlee hole punch before I discovered the Ripley HSK-19 Antenna Hole Saw. The description in the catalog states: Ripley hole saw for installing permanent mount antennas. Makes 3/4 hole and limits depth to 1/8... It is sold by Tessco as catalog number 14023. It's a lot less cumbersome than the hole punch method, but the user still needs to consider where the dome light and/or roof support ribs are located, before drilling. Funny how some people don't check these details! My disclaimer of financial interest in Ripley or Tessco applies- I'm just a satisfied customer. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Ken Arck Sent: Tuesday, February 20, 2007 7:42 AM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur At 07:29 AM 2/20/2007, you wrote: Ah, the good old days, when men armed with a drill and Greenlee punch thought nothing of putting holes in their roofs, fearing not the Wrath of Wife. ---When I bought my new Mustang last year, within 24 hours of bringing it home, I installed a genuine NMO mount in the trunk lid. Of course, I've always sworn by using Greenlee punches for the hole too (none of those stepped drill bits for me!) My wife didn't even question me, other than what took you so long? Ken
[Repeater-Builder] Re: Antennas that work both in commercial and amateur
--- In Repeater-Builder@yahoogroups.com, Ken Arck [EMAIL PROTECTED] wrote: At 07:29 AM 2/20/2007, you wrote: I have friends That think drilling a hole in a car or truck new or even a used one is a sin . I try not to but if necessary to get Antenna on ill go for the drill and Greenlee punch and I have a good one Hydraulic it will punch S/S up to 3 . DaleN8SAC Ah, the gold old days, when men armed with a drill and Greenlee punch thought nothing of putting holes in their roofs, fearing not the Wrath of Wife. Ken -- President and CTO - Arcom Communications Makers of the world famous RC210 Repeater Controller and accessories. http://www.arcomcontrollers.com/ Authorized Dealers for Kenwood and Telewave and we offer complete repeater packages! AH6LE/R - IRLP Node 3000 http://www.irlp.net
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
At 2/20/2007 18:08, you wrote: Ken, I, too, used a Greenlee hole punch before I discovered the Ripley HSK-19 Antenna Hole Saw. The description in the catalog states: Ripley hole saw for installing permanent mount antennas. Makes 3/4 hole and limits depth to 1/8... It is sold by Tessco as catalog number 14023. It's a lot less cumbersome than the hole punch method, but the user still needs to consider where the dome light and/or roof support ribs are located, before drilling. Funny how some people don't check these details! I'm by no means an expert in mobile installs. In fact, I'm quite a novice in that area probably always will be. However, I did discover one simple trick for locating the correct spot to drill the mounting hole: Remove the dome light locate the spot to drill from the bottom, through the dome light area so you know where you can put the hole have room for the coax. Then center-punch the spot from the bottom, making a raised dimple in the rooftop. Then take the punch to the rooftop, center it on the dimple punch again, inverting the dimple so you can then drill your mounting hole from the top. Also be careful to use either a quality hole saw, or one that's undersized by 1/16 in. The first 3/4 in. saw I used had a bit of wobble in it almost made the hole too big for the rooftop NMO mount. Boy would that have been embarrassing if the hole really had been too big the mount slipped through! Bob NO6B
Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
ocwarren2000 wrote: I've been watching this topic and cannot recommend the half wave dipole bay antennas as not really efficient gain wise for what one gets for the effort.. The Station Master series has been mentioned, which has good omnidirectional gain, in the order of some 10 db, and which is equal to having a 10 element beam in all directions!! Far above a 4 section dipole arrangment! As Laryn mentioned, the 10dB stationmasters are only available at UHF and above, because a 10dB version at 150Mhz (probably even 220) would be on the order of 40-50' long! In the same vertical space as a UHF 10dBd stationmaster, you can also put in an 8-bay folded dipole array (most commercial x-bay arrays use folded dipoles), which yields 9dBd. The advantage most find with the dipole arrays is that they are DC grounded, and are less susceptible to noise, rain static, etc. -- Jim Barbour WD8CHL
Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
Laryn Lohman wrote: --- In Repeater-Builder@yahoogroups.com, Barry C' [EMAIL PROTECTED] wrote: I presume its some sort of stacked arrangment , in chich case it will make that gain at resonance , Yes, the ASPB602 is four stacked dipoles, just like the DB224. My point again is that resonance is NOT a requirement for an effective and efficient antenna. Right-slightly OT, for a mobile antenna, you will find that you can squeak out a bit more gain by using a .64-wavelength whip instead of a pure 5/8-wave (.625) In the late 60's/early 70's, the NewTronics BBL series VHF gain antennas were rated at an honest 4dB gain-and did it. The A/S VHF gain antennas measured about 2 dB. They were actually end-fed 1/2-waves... If you can find an original BBL-144 still in good shape after 30+ years, keep it! -- Jim Barbour WD8CHL
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
-Original Message- From: Repeater-Builder@yahoogroups.com [mailto:Repeater- [EMAIL PROTECTED] On Behalf Of Jim B. Sent: Monday, February 19, 2007 12:42 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Laryn Lohman wrote: --- In Repeater-Builder@yahoogroups.com, Barry C' [EMAIL PROTECTED] wrote: I presume its some sort of stacked arrangment , in chich case it will make that gain at resonance , Yes, the ASPB602 is four stacked dipoles, just like the DB224. My point again is that resonance is NOT a requirement for an effective and efficient antenna. Right-slightly OT, for a mobile antenna, you will find that you can squeak out a bit more gain by using a .64-wavelength whip instead of a pure 5/8-wave (.625) In the late 60's/early 70's, the NewTronics BBL series VHF gain antennas were rated at an honest 4dB gain-and did it. The A/S VHF gain antennas measured about 2 dB. They were actually end-fed 1/2-waves... If you can find an original BBL-144 still in good shape after 30+ years, keep it! -- Jim Barbour WD8CHL Are you telling us that the difference in length between .64 wavelength and .625 wave length, a mere .015 (about 1.2 inches)amount, accounts for a full db of gain? How do you know they provided 4 db of gain? 73 Gary K4FMX
Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
Right-slightly OT, for a mobile antenna, you will find that you can squeak out a bit more gain by using a .64-wavelength whip instead of a pure 5/8-wave (.625) In the late 60's/early 70's, the NewTronics BBL series VHF gain antennas were rated at an honest 4dB gain-and did it. The A/S VHF gain antennas measured about 2 dB. They were actually end-fed 1/2-waves... If you can find an original BBL-144 still in good shape after 30+ years, keep it! -- Jim Barbour WD8CHL Are you telling us that the difference in length between .64 wavelength and .625 wave length, a mere .015 (about 1.2 inches)amount, accounts for a full db of gain? End result: 4dB gain over a 1/4-wave (should've specified that part). Not sure whether it was a full dB over a 5/8-but that was the peak in the gain curve. How do you know they provided 4 db of gain? 73 Gary K4FMX Measured on their range-they used to be based in Cleveland, and my father was one of the designers. (anybody here remember the PRO-27JR 27Mhz antenna? Or the original 4BTV?) -- Jim Barbour WD8CHL
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
-Original Message- From: Repeater-Builder@yahoogroups.com [mailto:Repeater- [EMAIL PROTECTED] On Behalf Of Jim B. Sent: Monday, February 19, 2007 4:32 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Right-slightly OT, for a mobile antenna, you will find that you can squeak out a bit more gain by using a .64-wavelength whip instead of a pure 5/8-wave (.625) In the late 60's/early 70's, the NewTronics BBL series VHF gain antennas were rated at an honest 4dB gain-and did it. The A/S VHF gain antennas measured about 2 dB. They were actually end-fed 1/2-waves... If you can find an original BBL-144 still in good shape after 30+ years, keep it! -- Jim Barbour WD8CHL Are you telling us that the difference in length between .64 wavelength and .625 wave length, a mere .015 (about 1.2 inches)amount, accounts for a full db of gain? End result: 4dB gain over a 1/4-wave (should've specified that part). Not sure whether it was a full dB over a 5/8-but that was the peak in the gain curve. How do you know they provided 4 db of gain? 73 Gary K4FMX Measured on their range-they used to be based in Cleveland, and my father was one of the designers. (anybody here remember the PRO-27JR 27Mhz antenna? Or the original 4BTV?) -- Jim Barbour WD8CHL With all due respect to your father Jim, I think that 4 db of gain is wishful thinking. A 5/8 wave length antenna theoretically is a little over 3 db and in real life 3 db is seldom realized. If I am not mistaken a .64 wavelength would have at most a tenth of a db advantage over a 5/8 antenna. 73 Gary K4FMX
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
Measured on their range-they used to be based in Cleveland, and my father was one of the designers. (anybody here remember the PRO-27JR 27Mhz antenna? Or the original 4BTV?) -- Jim Barbour WD8CHL With all due respect to your father Jim, I think that 4 db of gain is wishful thinking. A 5/8 wave length antenna theoretically is a little over 3 db and in real life 3 db is seldom realized. If I am not mistaken a .64 wavelength would have at most a tenth of a db advantage over a 5/8 antenna. 73 Gary K4FMX There are a lot of unknown variables here, including, but not limited to the size of the ground plane the antennas were mounted on, their heights above the ground plane, the method of coupling to the ground plane (direct, mag mount, etc.), matching networks' efficiencies, etc.. And more importantly, was the 4 dB gain a peak value, or at 0 degrees elevation? Typically a 5/8 wave over a perfect ground plane should be a little more than 3 dB better than a 1/4 wave on the horizon, but with so many unknowns and so much variability in mobile installations, there doesn't seem to be a definitive conclusion to be drawn here. Maybe Jim can provide more detail. --- Jeff
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
-Original Message- From: Repeater-Builder@yahoogroups.com [mailto:Repeater- [EMAIL PROTECTED] On Behalf Of Barry C' Sent: Friday, February 16, 2007 11:04 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur From: Laryn Lohman [EMAIL PROTECTED] Reply-To: Repeater-Builder@yahoogroups.com To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Date: Sat, 17 Feb 2007 03:45:51 - it's also not a stacked so bear little relevence to the matter Trying to understand what stacked has to do with the discussion... I am well aaware of what stacked means assume etc. There is little or no automatic penalty for using a non-resonant antenna. just some efficiency Barry, try to understand that a resonant antenna is not automatically efficient. And conversely that a non-resonant antenna is automatically inefficient. There is much mis-information out there, and it dies very slowly. why not have a read of some of the wiki material about broadcasting that we have made availible ? I have a understand suffucuent to have managed a living for some years in the telecoms game . I would venture a guess that there are a great number of people on this list that have/are making a living in the telecoms game. Is there something unique about the broadcast industry that makes the laws of physics work differently than they do in the two way radio industry? Also note that time spent in any industry doesn't automatically make one an expert there either. Unless of course you have a PhD in that particular phase of that industry, then you may be eligible to be considered an expert on the subject. 73 Gary K4FMX
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
-Original Message- From: Repeater-Builder@yahoogroups.com [mailto:Repeater- [EMAIL PROTECTED] On Behalf Of Barry C' Sent: Friday, February 16, 2007 10:59 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur From: Gary Schafer [EMAIL PROTECTED] Reply-To: Repeater-Builder@yahoogroups.com To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Date: Fri, 16 Feb 2007 19:31:17 -0500 -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:Repeater- [EMAIL PROTECTED] On Behalf Of Barry C' Sent: Friday, February 16, 2007 6:15 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur From: Laryn Lohman [EMAIL PROTECTED] Reply-To: Repeater-Builder@yahoogroups.com To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Date: Fri, 16 Feb 2007 17:33:49 - --- In Repeater-Builder@yahoogroups.com, Barry C' [EMAIL PROTECTED] wrote: I presume its some sort of stacked arrangment , in chich case it will make that gain at resonance , Yes, the ASPB602 is four stacked dipoles, just like the DB224. My point again is that resonance is NOT a requirement for an effective and efficient antenna. The wider frequency coverage for this antenna is likely because the dipoles are fabricated from 3/4 in. OD tubing instead of 3/8 in. tubing. or as in many cases of commercial sticks its almost a dummy load in reactance ( think about it) I must admit brandishing model number does no good as I am not familiar , its been a long time since I was at broadcast school so I am unlikly to change methodology now :) A collinear antenna is not as wide band as a dipole antenna because each element of a collinear is fed from the previous element. When changing frequency there is a phase shift at the end of each element. That phase shift is cumulative and by the time it gets to the higher elements the phase shift can be significant. That destroys the pattern of the antenna and thus the gain. With a dipole antenna all the elements are fed from the same source so you don't have that same kind of phase shift from element to element and the pattern remains more intact with a shift in frequency. Yes there is some phase shift in the phasing/feed lines to the dipole elements that eventually disrupts the pattern of the antenna and thus the gain. But this type of antenna can be operated over a much wider range than a collinear type. Swr on the antenna only becomes a problem when it gets high enough that the transmitter can no longer be matched or it is excessive and caused excessive feed line loss. By using fatter elements it provides for a broader Swr and makes matching easier. Does any of this fit with your methodology? :) 73 Gary K4FMX Thanks for trying to teach how to suck eggs The dia of a radiator has to be incresed to a noticable portion of the wavelength in use to appreciably increas useable bandwidth , an excursion of 2%/Frq does produce a noticable drop in response and gain , just because the swr is acceptable does not the thing a decent radiator , I suggest you spend a day on a rabge some time and do some tests , when I have some time I will pursue it further but atm I have to finsih sorting out the next $ generation project. B A shift of 2% may produce a noticeable drop in gain in an antenna system but not for the reasons you seem to be expressing. The water seems to be getting a little muddy here and it is becoming a little difficult determining as to what you are comparing your reasoning to. Some times you seem to be discussing multiple element antennas and other times a single element antenna. Maybe you could give us an example of a particular type of antenna and tell us why the gain drops on that antenna when frequency is changed. 73 Gary K4FMX
[Repeater-Builder] Re: Antennas that work both in commercial and amateur
--- In Repeater-Builder@yahoogroups.com, skipp025 [EMAIL PROTECTED] wrote: If you are going to use this Antenna to work on and test radio's need a split of 135 to 174 I don't that will be possible, Most antenna will cover that range but you have to trim them for a certain Freq some are trimmed at Factory some user has to trim . As per the difference between Commercial and ham antennas usually the commercial antennas are better built will withstand more wind load last longer with less service , But I don't think would have any better signal . I use both for ham Have a chushcraft 26-b2 has been in use for 9 years works as good as day I put up . Also have a commercial Dipole stacked 4 which has been in use for same amount of time . Both are on 30' tower if I was going to put on tower above 100' would want the best antenna I could find or Buy would be a whole lot cheaper than having to replace often . Jed Barton jed@ wrote: Hey guys, I need some suggestions. I need a vhf and a uhf antena. Here's the requirement. I'm planning to operate both amateur and commercial stuff from the house. I'd rather not use a ham antenna in the commercial bands. Are there some that'll do the 136 to 174 split, and some UHF that'll do like 439 to 490? Any ideas? Thanks, Jed
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
Well lets look at the riddle , swinging a radiator acree 20 or 30 megs of bandwidth it will tune and still radiate but will it have appreciable gain away from certain design points? I think not . Laryn K8TVZ where did I mention resonance ? resonance of course being point normally considered highest gain so matching 30 ft of wire and 1.85 megs wont work terribly well will it ? Resonance has nothing to do with the amount of gain an antenna has. Resonance only means that capacitive and inductive reactance are equal. Yes 30 feet of wire on 1.85 megs will radiate nearly as well as 240 feet will. The problem with 30 feet of wire will be getting power to it as the impedance is so low the loss in the matching network will be quite high. An antenna having to be resonant in order to be efficient is a common misconception by many. 73 Gary K4FMX
[Repeater-Builder] Re: Antennas that work both in commercial and amateur
--- In Repeater-Builder@yahoogroups.com, Yahoo [EMAIL PROTECTED] wrote: There are a number of old post on this subject. Take a look at the 4 bay dipole antennas from Antenex (made by Bluewave). VERY broadband. As for whether or not they are expensive is a matter of personal opinion. Jeff -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Jed Barton Sent: Thursday, February 15, 2007 12:14 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Antennas that work both in commercial and amateur Hey guys, I need some suggestions. I need a vhf and a uhf antena. Here's the requirement. I'm planning to operate both amateur and commercial stuff from the house. I'd rather not use a ham antenna in the commercial bands. Are there some that'll do the 136 to 174 split, and some UHF that'll do like 439 to 490? Any ideas? Thanks, Jed I've been watching this topic and cannot recommend the half wave dipole bay antennas as not really efficient gain wise for what one gets for the effort.. The Station Master series has been mentioned, which has good omnidirectional gain, in the order of some 10 db, and which is equal to having a 10 element beam in all directions!! Far above a 4 section dipole arrangment! The Station Master series is made of stacked coaxial sections inside the fiberglass. Unsolder the wire from the top metal cap and unscrew the cap and look inside. First you will find that there is a quarter wave element at the top, then phased half wave coax sections below that. Research staked Coaxial vertal antennas on the Internet, they're well covered. I favor them as out performing most anythinb else. Gonset discovered back in the 1960's era that the bandwidth aspect of a halfwave antenna was the results of the ratio of the thickness of the half wave antenna to the half wave length, and reinvented the bow tie antenna, typically used for broadband TV!!! Hahahahaha!!! It also depends on the radiation pattern, where it goes and how narrow it is. I've had a single section coaxial vertical antenna, basically a half wave vertical, mounted at ground level, out perform a mobile 5/8th wave 3 db gain vertical, mounted on my vehicle out in the driveway, with the same radio, but a few feet higher!! The mobile 5/8th wave puts out a very narrow pattern at horizon level, and the coaxial a wider donut shaped pattern also at the horizon.. While I think it said that the proposed antenna is to be on top of a building, the same antenna on a mountain top repeater has to do the same job in the weather, and over time, whether it's an Amateur Radio or Commercial installation..!!! Best, Dick
[Repeater-Builder] Re: Antennas that work both in commercial and amateur
--- In Repeater-Builder@yahoogroups.com, Barry C' [EMAIL PROTECTED] wrote: I presume its some sort of stacked arrangment , in chich case it will make that gain at resonance , Yes, the ASPB602 is four stacked dipoles, just like the DB224. My point again is that resonance is NOT a requirement for an effective and efficient antenna. The wider frequency coverage for this antenna is likely because the dipoles are fabricated from 3/4 in. OD tubing instead of 3/8 in. tubing. For example, most AM broadcast antennas (towers) are not resonant at their operating frequency. In fact, more and more AM broadcasters are diplexing, and even occasionally triplexing. So stations on 820 kc. and 1290 kc. might use the same antenna. Is the antenna resonant? No. There is little or no automatic penalty for using a non-resonant antenna. Ask anyone on this list how well the DB420 works down into the 70cm ham gand. claims are like water (sic) Very true. The claims I make here (6dbd gain and 144-162 mc. at less than 1.5:1 VSWR) are quoted from reputable commercial two-way antenna manufacturer's data sheets and catalogs, not some ham-grade antenna gain claim. Laryn K8TVZ
[Repeater-Builder] Re: Antennas that work both in commercial and amateur
I've been watching this topic and cannot recommend the half wave dipole bay antennas as not really efficient gain wise for what one gets for the effort.. The Station Master series has been mentioned, which has good omnidirectional gain, in the order of some 10 db, and which is equal to having a 10 element beam in all directions!! Far above a 4 section dipole arrangment! You are comparing totally different antennas. If you are going to talk about the Stationmaster with 10 dbd of omni gain, you are referring to a UHF antenna. The comparably-sized exposed-dipole antenna is a DB420 with 9.2 dbd gain. It has eight (basically), stacked dipoles, not four. Same basic length, same basic gain, and the 420 covers far more bandwidth. The Station Master series is made of stacked coaxial sections inside the fiberglass. Unsolder the wire from the top metal cap and unscrew the cap and look inside. First you will find that there is a quarter wave element at the top, then phased half wave coax sections below that. Research staked Coaxial vertal antennas on the Internet, they're well covered. I favor them as out performing most anythinb else. What are you basing your out performing claim on? Gonset discovered back in the 1960's era that the bandwidth aspect of a halfwave antenna was the results of the ratio of the thickness of the half wave antenna to the half wave length, and reinvented the bow tie antenna, typically used for broadband TV!!! Hahahahaha!!! It also depends on the radiation pattern, where it goes and how narrow it is. I've had a single section coaxial vertical antenna, basically a half wave vertical, mounted at ground level, out perform a mobile 5/8th wave 3 db gain vertical, mounted on my vehicle out in the driveway, with the same radio, but a few feet higher!! The mobile 5/8th wave puts out a very narrow pattern at horizon level, and the coaxial a wider donut shaped pattern also at the horizon.. It is very misleading to compare two antennas in a multipath-laden area such the typical driveway, especially if not mounted in the same EXACT place. Move an antenna to a new position a foot or two or ten away and you'll find completely new signal readings. You've experienced mobile flutter I'm sure. Same thing. While I think it said that the proposed antenna is to be on top of a building, the same antenna on a mountain top repeater has to do the same job in the weather, and over time, whether it's an Amateur Radio or Commercial installation..!!! Best, Dick Laryn K8TVZ
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
And does not turn into toothpicks when struck by lightning! Paul -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Laryn Lohman Sent: Friday, February 16, 2007 12:29 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur I've been watching this topic and cannot recommend the half wave dipole bay antennas as not really efficient gain wise for what one gets for the effort.. The Station Master series has been mentioned, which has good omnidirectional gain, in the order of some 10 db, and which is equal to having a 10 element beam in all directions!! Far above a 4 section dipole arrangment! You are comparing totally different antennas. If you are going to talk about the Stationmaster with 10 dbd of omni gain, you are referring to a UHF antenna. The comparably-sized exposed-dipole antenna is a DB420 with 9.2 dbd gain. It has eight (basically), stacked dipoles, not four. Same basic length, same basic gain, and the 420 covers far more bandwidth. The Station Master series is made of stacked coaxial sections inside the fiberglass. Unsolder the wire from the top metal cap and unscrew the cap and look inside. First you will find that there is a quarter wave element at the top, then phased half wave coax sections below that. Research staked Coaxial vertal antennas on the Internet, they're well covered. I favor them as out performing most anythinb else. What are you basing your out performing claim on? Gonset discovered back in the 1960's era that the bandwidth aspect of a halfwave antenna was the results of the ratio of the thickness of the half wave antenna to the half wave length, and reinvented the bow tie antenna, typically used for broadband TV!!! Hahahahaha!!! It also depends on the radiation pattern, where it goes and how narrow it is. I've had a single section coaxial vertical antenna, basically a half wave vertical, mounted at ground level, out perform a mobile 5/8th wave 3 db gain vertical, mounted on my vehicle out in the driveway, with the same radio, but a few feet higher!! The mobile 5/8th wave puts out a very narrow pattern at horizon level, and the coaxial a wider donut shaped pattern also at the horizon.. It is very misleading to compare two antennas in a multipath-laden area such the typical driveway, especially if not mounted in the same EXACT place. Move an antenna to a new position a foot or two or ten away and you'll find completely new signal readings. You've experienced mobile flutter I'm sure. Same thing. While I think it said that the proposed antenna is to be on top of a building, the same antenna on a mountain top repeater has to do the same job in the weather, and over time, whether it's an Amateur Radio or Commercial installation..!!! Best, Dick Laryn K8TVZ Yahoo! Groups Links -- No virus found in this incoming message. Checked by AVG Free Edition. Version: 7.5.441 / Virus Database: 268.18.0/689 - Release Date: 2/15/2007 5:40 PM -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.5.441 / Virus Database: 268.18.0/689 - Release Date: 2/15/2007 5:40 PM p class=style1Visit a href=http://www.ourphonelist.com;OurPhonelist.combrIt's free and you'll never lose track of a phone number again! /a/p Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) * To change settings via email: mailto:[EMAIL PROTECTED] mailto:[EMAIL PROTECTED] * To unsubscribe from this group, send an email to: [EMAIL PROTECTED] * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
From: Gary Schafer [EMAIL PROTECTED] Reply-To: Repeater-Builder@yahoogroups.com To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Date: Fri, 16 Feb 2007 10:40:47 -0500 Well lets look at the riddle , swinging a radiator acree 20 or 30 megs of bandwidth it will tune and still radiate but will it have appreciable gain away from certain design points? I think not . Laryn K8TVZ where did I mention resonance ? resonance of course being point normally considered highest gain so matching 30 ft of wire and 1.85 megs wont work terribly well will it ? Resonance has nothing to do with the amount of gain an antenna has. Resonance only means that capacitive and inductive reactance are equal. I see we subscribe to differing methodologys , I dont agree but no matter . Yes 30 feet of wire on 1.85 megs will radiate nearly as well as 240 feet will. The problem with 30 feet of wire will be getting power to it as the impedance is so low the loss in the matching network will be quite high. An antenna having to be resonant in order to be efficient is a common misconception by many. see above 73 Gary K4FMX _ Advertisement: Fresh jobs daily. Stop waiting for the newspaper. Search Now! www.seek.com.au http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fninemsn%2Eseek%2Ecom%2Eau_t=757263760_r=Hotmail_EndText_Dec06_m=EXT
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
From: Laryn Lohman [EMAIL PROTECTED] Reply-To: Repeater-Builder@yahoogroups.com To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Date: Fri, 16 Feb 2007 17:33:49 - --- In Repeater-Builder@yahoogroups.com, Barry C' [EMAIL PROTECTED] wrote: I presume its some sort of stacked arrangment , in chich case it will make that gain at resonance , Yes, the ASPB602 is four stacked dipoles, just like the DB224. My point again is that resonance is NOT a requirement for an effective and efficient antenna. The wider frequency coverage for this antenna is likely because the dipoles are fabricated from 3/4 in. OD tubing instead of 3/8 in. tubing. or as in many cases of commercial sticks its almost a dummy load in reactance ( think about it) I must admit brandishing model number does no good as I am not familiar , its been a long time since I was at broadcast school so I am unlikly to change methodology now :) For example, most AM broadcast antennas (towers) are not resonant at their operating frequency. In fact, more and more AM broadcasters are diplexing, and even occasionally triplexing. So stations on 820 kc. and 1290 kc. might use the same antenna. Is the antenna resonant? No. it's also not a stacked so bear little relevence to the matter There is little or no automatic penalty for using a non-resonant antenna. just some efficiency Ask anyone on this list how well the DB420 works down into the 70cm ham gand. claims are like water (sic) Very true. The claims I make here (6dbd gain and 144-162 mc. at less than 1.5:1 VSWR) are quoted from reputable commercial two-way antenna manufacturer's data sheets and catalogs, not some ham-grade antenna gain claim. interesting comparison and I doubt you meant to insult hams as a group Laryn K8TVZ _ Advertisement: 50% off on Xbox 360, PS and Nintendo Wii titles! http://www.play-asia.com/SOap-23-83-4lab-71-bn-49-en-84-k-40-extended.html
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
--- Barry C' [EMAIL PROTECTED] wrote: Yes, the ASPB602 is four stacked dipoles, just like the DB224. My point again is that resonance is NOT a requirement for an effective and efficient antenna. The wider frequency coverage for this antenna is likely because the dipoles are fabricated from 3/4 in. OD tubing instead of 3/8 in. tubing. or as in many cases of commercial sticks its almost a dummy load in reactance ( think about it) I must admit brandishing model number does no good as I am not familiar , its been a long time since I was at broadcast school so I am unlikly to change methodology now :) Here is a link to the data sheet on the antenna I'm talking about. http://www.telewave.com/pdf/TWDS-7045.pdf These are wideband and high gain. Joe Get your own web address. Have a HUGE year through Yahoo! Small Business. http://smallbusiness.yahoo.com/domains/?p=BESTDEAL
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
-Original Message- From: Repeater-Builder@yahoogroups.com [mailto:Repeater- [EMAIL PROTECTED] On Behalf Of Barry C' Sent: Friday, February 16, 2007 6:15 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur From: Laryn Lohman [EMAIL PROTECTED] Reply-To: Repeater-Builder@yahoogroups.com To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Date: Fri, 16 Feb 2007 17:33:49 - --- In Repeater-Builder@yahoogroups.com, Barry C' [EMAIL PROTECTED] wrote: I presume its some sort of stacked arrangment , in chich case it will make that gain at resonance , Yes, the ASPB602 is four stacked dipoles, just like the DB224. My point again is that resonance is NOT a requirement for an effective and efficient antenna. The wider frequency coverage for this antenna is likely because the dipoles are fabricated from 3/4 in. OD tubing instead of 3/8 in. tubing. or as in many cases of commercial sticks its almost a dummy load in reactance ( think about it) I must admit brandishing model number does no good as I am not familiar , its been a long time since I was at broadcast school so I am unlikly to change methodology now :) A collinear antenna is not as wide band as a dipole antenna because each element of a collinear is fed from the previous element. When changing frequency there is a phase shift at the end of each element. That phase shift is cumulative and by the time it gets to the higher elements the phase shift can be significant. That destroys the pattern of the antenna and thus the gain. With a dipole antenna all the elements are fed from the same source so you don't have that same kind of phase shift from element to element and the pattern remains more intact with a shift in frequency. Yes there is some phase shift in the phasing/feed lines to the dipole elements that eventually disrupts the pattern of the antenna and thus the gain. But this type of antenna can be operated over a much wider range than a collinear type. Swr on the antenna only becomes a problem when it gets high enough that the transmitter can no longer be matched or it is excessive and caused excessive feed line loss. By using fatter elements it provides for a broader Swr and makes matching easier. Does any of this fit with your methodology? :) 73 Gary K4FMX
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
Hi Jed. If you're not interested in a lot of gain, try a discone. They're about as broadbanded as you can get, and not too expensive. I bought one from the local ham shop in Newington for less than $100. It's good for 2 meters and up. I've seen some discones designed for scanners that have a loaded whip out the top to resonate down to low bands. It's not too broadbanded at this low band frequency, since it's almost like a regular hamstick or other loaded antenna. Still. The discone part work pretty well at the frequencies it's designed for. Discones are like high pass filters. A discone built for 2 meters will work up to almost microwave frequencies. Great for a test antenna. 73 de N1FNE _ From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Maxwell D Pratt Sent: Friday, February 16, 2007 11:13 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur --- In Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com, skipp025 [EMAIL PROTECTED] wrote: If you are going to use this Antenna to work on and test radio's need a split of 135 to 174 I don't that will be possible, Most antenna will cover that range but you have to trim them for a certain Freq some are trimmed at Factory some user has to trim . As per the difference between Commercial and ham antennas usually the commercial antennas are better built will withstand more wind load last longer with less service , But I don't think would have any better signal . I use both for ham Have a chushcraft 26-b2 has been in use for 9 years works as good as day I put up . Also have a commercial Dipole stacked 4 which has been in use for same amount of time . Both are on 30' tower if I was going to put on tower above 100' would want the best antenna I could find or Buy would be a whole lot cheaper than having to replace often . Jed Barton jed@ wrote: Hey guys, I need some suggestions. I need a vhf and a uhf antena. Here's the requirement. I'm planning to operate both amateur and commercial stuff from the house. I'd rather not use a ham antenna in the commercial bands. Are there some that'll do the 136 to 174 split, and some UHF that'll do like 439 to 490? Any ideas? Thanks, Jed
[Repeater-Builder] Re: Antennas that work both in commercial and amateur
it's also not a stacked so bear little relevence to the matter Trying to understand what stacked has to do with the discussion... There is little or no automatic penalty for using a non-resonant antenna. just some efficiency Barry, try to understand that a resonant antenna is not automatically efficient. And conversely that a non-resonant antenna is automatically inefficient. There is much mis-information out there, and it dies very slowly. Ask anyone on this list how well the DB420 works down into the 70cm ham gand. claims are like water (sic) Very true. The claims I make here (6dbd gain and 144-162 mc. at less than 1.5:1 VSWR) are quoted from reputable commercial two-way antenna manufacturer's data sheets and catalogs, not some ham-grade antenna gain claim. interesting comparison and I doubt you meant to insult hams as a group Whoa, insult?? The term ham-grade as used here simply separates the reputable and known-to-be-honest-about-gain manufacturers from those that are obviously not-so-honest. 'Nuff said. Apparently you've not read some of the incredible claims of ham-grade antennas. They sometimes re-invent the laws of physics. Amazing! Laryn K8TVZ
Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
I have a rubber duck that outperforms three different MFR's discones. Joe M. Rod Lane wrote: Hi Jed. If youre not interested in a lot of gain, try a discone. Theyre about as broadbanded as you can get, and not too expensive. I bought one from the local ham shop in Newington for less than $100. Its good for 2 meters and up. Ive seen some discones designed for scanners that have a loaded whip out the top to resonate down to low bands. Its not too broadbanded at this low band frequency, since its almost like a regular hamstick or other loaded antenna. Still. The discone part work pretty well at the frequencies its designed for. Discones are like high pass filters. A discone built for 2 meters will work up to almost microwave frequencies. Great for a test antenna. 73 de N1FNE -- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Maxwell D Pratt Sent: Friday, February 16, 2007 11:13 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur --- In Repeater-Builder@yahoogroups.com, skipp025 [EMAIL PROTECTED] wrote: If you are going to use this Antenna to work on and test radio's need a split of 135 to 174 I don't that will be possible, Most antenna will cover that range but you have to trim them for a certain Freq some are trimmed at Factory some user has to trim . As per the difference between Commercial and ham antennas usually the commercial antennas are better built will withstand more wind load last longer with less service , But I don't think would have any better signal . I use both for ham Have a chushcraft 26-b2 has been in use for 9 years works as good as day I put up . Also have a commercial Dipole stacked 4 which has been in use for same amount of time . Both are on 30' tower if I was going to put on tower above 100' would want the best antenna I could find or Buy would be a whole lot cheaper than having to replace often . Jed Barton jed@ wrote: Hey guys, I need some suggestions. I need a vhf and a uhf antena. Here's the requirement. I'm planning to operate both amateur and commercial stuff from the house. I'd rather not use a ham antenna in the commercial bands. Are there some that'll do the 136 to 174 split, and some UHF that'll do like 439 to 490? Any ideas? Thanks, Jed
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
From: Gary Schafer [EMAIL PROTECTED] Reply-To: Repeater-Builder@yahoogroups.com To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Date: Fri, 16 Feb 2007 19:31:17 -0500 -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:Repeater- [EMAIL PROTECTED] On Behalf Of Barry C' Sent: Friday, February 16, 2007 6:15 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur From: Laryn Lohman [EMAIL PROTECTED] Reply-To: Repeater-Builder@yahoogroups.com To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Date: Fri, 16 Feb 2007 17:33:49 - --- In Repeater-Builder@yahoogroups.com, Barry C' [EMAIL PROTECTED] wrote: I presume its some sort of stacked arrangment , in chich case it will make that gain at resonance , Yes, the ASPB602 is four stacked dipoles, just like the DB224. My point again is that resonance is NOT a requirement for an effective and efficient antenna. The wider frequency coverage for this antenna is likely because the dipoles are fabricated from 3/4 in. OD tubing instead of 3/8 in. tubing. or as in many cases of commercial sticks its almost a dummy load in reactance ( think about it) I must admit brandishing model number does no good as I am not familiar , its been a long time since I was at broadcast school so I am unlikly to change methodology now :) A collinear antenna is not as wide band as a dipole antenna because each element of a collinear is fed from the previous element. When changing frequency there is a phase shift at the end of each element. That phase shift is cumulative and by the time it gets to the higher elements the phase shift can be significant. That destroys the pattern of the antenna and thus the gain. With a dipole antenna all the elements are fed from the same source so you don't have that same kind of phase shift from element to element and the pattern remains more intact with a shift in frequency. Yes there is some phase shift in the phasing/feed lines to the dipole elements that eventually disrupts the pattern of the antenna and thus the gain. But this type of antenna can be operated over a much wider range than a collinear type. Swr on the antenna only becomes a problem when it gets high enough that the transmitter can no longer be matched or it is excessive and caused excessive feed line loss. By using fatter elements it provides for a broader Swr and makes matching easier. Does any of this fit with your methodology? :) 73 Gary K4FMX Thanks for trying to teach how to suck eggs The dia of a radiator has to be incresed to a noticable portion of the wavelength in use to appreciably increas useable bandwidth , an excursion of 2%/Frq does produce a noticable drop in response and gain , just because the swr is acceptable does not the thing a decent radiator , I suggest you spend a day on a rabge some time and do some tests , when I have some time I will pursue it further but atm I have to finsih sorting out the next $ generation project. B _ Advertisement: Fresh jobs daily. Stop waiting for the newspaper. Search Now! www.seek.com.au http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fninemsn%2Eseek%2Ecom%2Eau_t=757263760_r=Hotmail_EndText_Dec06_m=EXT
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
From: Laryn Lohman [EMAIL PROTECTED] Reply-To: Repeater-Builder@yahoogroups.com To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Date: Sat, 17 Feb 2007 03:45:51 - it's also not a stacked so bear little relevence to the matter Trying to understand what stacked has to do with the discussion... I am well aaware of what stacked means assume etc. There is little or no automatic penalty for using a non-resonant antenna. just some efficiency Barry, try to understand that a resonant antenna is not automatically efficient. And conversely that a non-resonant antenna is automatically inefficient. There is much mis-information out there, and it dies very slowly. why not have a read of some of the wiki material about broadcasting that we have made availible ? I have a understand suffucuent to have managed a living for some years in the telecoms game . Ask anyone on this list how well the DB420 works down into the 70cm ham gand. claims are like water (sic) Very true. The claims I make here (6dbd gain and 144-162 mc. at less than 1.5:1 VSWR) are quoted from reputable commercial two-way antenna manufacturer's data sheets and catalogs, not some ham-grade antenna gain claim. interesting comparison and I doubt you meant to insult hams as a group Whoa, insult?? The term ham-grade as used here simply separates the reputable and known-to-be-honest-about-gain manufacturers from those that are obviously not-so-honest. 'Nuff said. Apparently you've not read some of the incredible claims of ham-grade antennas. They sometimes re-invent the laws of physics. Amazing! well there are geese in every area of life , I belive what my instrukents tell me on the range . Laryn K8TVZ _ Join the millions of Australians using Live Search. Try live.com.au http://ninemsn.com.au/share/redir/adTrack.asp?mode=clickclientID=740referral=millionURL=http://live.com.au
Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
At 2/15/2007 19:10, you wrote: --- In Repeater-Builder@yahoogroups.com, Barry C' [EMAIL PROTECTED] wrote: I would have to suggest any copper that has a huge bandwidth will have gain on only one tuned area , Well, actually no. Resonance is not a requirement for an effective antenna with broadband gain. The only requirement is that the RF be brought to and from the antenna by an effective matching system. A fine example of broadband gain is the log periodic. However, having said that I think you'll have a hard time finding a broadband antenna with high omnidirectional gain, or at least one that is reasonably space-efficient. Bob NO6B
Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
At 2/16/2007 18:26, you wrote: I have a rubber duck that outperforms three different MFR's discones. If I understand it correctly, the discone is nothing more than a ground plane-imaged 3D bowtie, IOW a very simple design. What could go wrong? Bob NO6B
[Repeater-Builder] Re: Antennas that work both in commercial and amateur
Sinclair makes what you're looking for... but you won't like the price... and if their customer service is still as bad as my last experience you won't enjoy trying to resolve any problems that might pop up. cheers, skipp Jed Barton [EMAIL PROTECTED] wrote: Hey guys, I need some suggestions. I need a vhf and a uhf antena. Here's the requirement. I'm planning to operate both amateur and commercial stuff from the house. I'd rather not use a ham antenna in the commercial bands. Are there some that'll do the 136 to 174 split, and some UHF that'll do like 439 to 490? Any ideas? Thanks, Jed
[Repeater-Builder] Re: Antennas that work both in commercial and amateur
Yep... About $10K to $15K worth of crap VHF Antennas bad... Doesn't keep me from buying more... just not the model/type we bought with the problems that have yet to be resolved. I only get a chance to grind on them about it at IWCE each year... every year. Overall Sinclair makes and made great stuff. But I have a large collection of VHF Aluminum Sinclair Edsels in my collection. cheers, skipp Jed Barton [EMAIL PROTECTED] wrote: wow, really, that bad? _ From: skipp025 [mailto:[EMAIL PROTECTED] Sent: Thursday, February 15, 2007 3:36 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Sinclair makes what you're looking for... but you won't like the price... and if their customer service is still as bad as my last experience you won't enjoy trying to resolve any problems that might pop up. cheers, skipp Jed Barton jed@ wrote: Hey guys, I need some suggestions. I need a vhf and a uhf antena. Here's the requirement. I'm planning to operate both amateur and commercial stuff from the house. I'd rather not use a ham antenna in the commercial bands. Are there some that'll do the 136 to 174 split, and some UHF that'll do like 439 to 490? Any ideas? Thanks, Jed
[Repeater-Builder] Re: Antennas that work both in commercial and amateur
Re: Antennas that work both in commercial and amateur
If you find one, it would have to be pretty low gain (like Unity).
Not really... but as the nature of the bandwidth beast is dealt
with... the 4 dipole antenna gain is not super high (about ~3db).
The dipole antenna I have the problem with is the first version of
SRL235NM Antennal model.
The SRL235NM makes an over priced coat hanger but a lousy repeater/
radio antenna.
Check out the SD2352 if you have time. They spec 5db gain from
138-174 MHz. But it's also a real monster to mount on a tower...
cheers,
skipp
[Repeater-Builder] Re: Antennas that work both in commercial and amateur
--- In Repeater-Builder@yahoogroups.com, mch [EMAIL PROTECTED] wrote: If you find one, it would have to be pretty low gain (like Unity). Joe M. Not necessarily Joe. I have a ASPB-602 which is an Antenna Specialists number. It is listed in a DB Products catalog from 1996, and is rated for 144-162 mc. I've run numerous unscientific tests comparing it to unmodified DB224s at the same mounting position and same feedline. Generally better gain than the DB224s. SWR sweep tests show very flat from 144-162 mc. It has large 3/4in OD elements; the DB224 have 3/8 OD elements. Better bandwidth. Unfortunately, I don't think it is made anymore. Laryn K8TVZ
Re: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
I've had issues with the customer service folks at Sinclair also. Will avoid them in the future when I can. Had a circulator that showed up and can't be tuned with the normal adjustments to get it back on track. After several excuses of needing a tax number and then some other documentation, they just stopped answering my emails asking for an RMA. Two years later, I've given up. YMMV Chuck n0nhj skipp025 wrote: Yep... About $10K to $15K worth of crap VHF Antennas bad... Doesn't keep me from buying more... just not the model/type we bought with the problems that have yet to be resolved. I only get a chance to grind on them about it at IWCE each year... every year. Overall Sinclair makes and made great stuff. But I have a large collection of VHF Aluminum Sinclair Edsels in my collection. cheers, skipp Jed Barton [EMAIL PROTECTED] wrote: wow, really, that bad? _ From: skipp025 [mailto:[EMAIL PROTECTED] Sent: Thursday, February 15, 2007 3:36 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Sinclair makes what you're looking for... but you won't like the price... and if their customer service is still as bad as my last experience you won't enjoy trying to resolve any problems that might pop up. cheers, skipp Jed Barton jed@ wrote: Hey guys, I need some suggestions. I need a vhf and a uhf antena. Here's the requirement. I'm planning to operate both amateur and commercial stuff from the house. I'd rather not use a ham antenna in the commercial bands. Are there some that'll do the 136 to 174 split, and some UHF that'll do like 439 to 490? Any ideas? Thanks, Jed Yahoo! Groups Links
[Repeater-Builder] Re: Antennas that work both in commercial and amateur
--- In Repeater-Builder@yahoogroups.com, Barry C' [EMAIL PROTECTED] wrote: I would have to suggest any copper that has a huge bandwidth will have gain on only one tuned area , Well, actually no. Resonance is not a requirement for an effective antenna with broadband gain. The only requirement is that the RF be brought to and from the antenna by an effective matching system. Laryn K8TVZ
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
Well lets look at the riddle , swinging a radiator acree 20 or 30 megs of bandwidth it will tune and still radiate but will it have appreciable gain away from certain design points? I think not . From: Laryn Lohman [EMAIL PROTECTED] Reply-To: Repeater-Builder@yahoogroups.com To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Date: Fri, 16 Feb 2007 03:10:59 - --- In Repeater-Builder@yahoogroups.com, Barry C' [EMAIL PROTECTED] wrote: I would have to suggest any copper that has a huge bandwidth will have gain on only one tuned area , Well, actually no. Resonance is not a requirement for an effective antenna with broadband gain. The only requirement is that the RF be brought to and from the antenna by an effective matching system. Laryn K8TVZ where did I mention resonance ? resonance of course being point normally considered highest gain so matching 30 ft of wire and 1.85 megs wont work terribly well will it ? _ Advertisement: Amazing holiday rentals? http://a.ninemsn.com.au/b.aspx?URL=http%3A%2F%2Fwww%2Eninemsn%2Erealestate%2Ecom%2Eau%2Fcgi%2Dbin%2Frsearch%3Fa%3Dbhp%26t%3Dhol%26cu%3DMSN_t=758874163_r=HM_Txt_Link_Holiday_Oct06_m=EXT
[Repeater-Builder] Re: Antennas that work both in commercial and amateur
--- In Repeater-Builder@yahoogroups.com, Barry C' [EMAIL PROTECTED] wrote: Well lets look at the riddle , swinging a radiator acree 20 or 30 megs of bandwidth it will tune and still radiate but will it have appreciable gain away from certain design points? I think not . OK, within certain unspecified parameters, I would agree. Let's be more specific. I referred to the ASPB602 in an earlier post, which has 6 or 9 dbd gain, depending on dipole configuration around the mast (normal for four stacked dipoles), and bandwidth of 144-162 mc (wider than most antennas in this range). Just trying to understand Barry, do you agree that these specs are valid? Depending on your answer, we can discuss further... Laryn K8TVZ
RE: [Repeater-Builder] Re: Antennas that work both in commercial and amateur
--- Barry C' [EMAIL PROTECTED] wrote: From: Laryn Lohman [EMAIL PROTECTED] Reply-To: Repeater-Builder@yahoogroups.com To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: Antennas that work both in commercial and amateur Date: Fri, 16 Feb 2007 05:04:02 - --- In Repeater-Builder@yahoogroups.com, Barry C' [EMAIL PROTECTED] wrote: Well lets look at the riddle , swinging a radiator acree 20 or 30 megs of bandwidth it will tune and still radiate but will it have appreciable gain away from certain design points? I think not . OK, within certain unspecified parameters, I would agree. Let's be more specific. I referred to the ASPB602 in an earlier post, which has 6 or 9 dbd gain, depending on dipole configuration around the mast (normal for four stacked dipoles), and bandwidth of 144-162 mc (wider than most antennas in this range). Just trying to understand Barry, do you agree that these specs are valid? Depending on your answer, we can discuss further... I presume its some sort of stacked arrangment , in chich case it will make that gain at resonance , claims are like water (sic) Laryn K8TVZ We have a couple of the Telewave broadband antennas, and they do seem to exhibit the gain over the advertised bandwidth. They are rated at 138-174, and do have good SWR over that range, and good gain. They replaced DB224 antennas at the same locations on the tower, and give exactly the same coverage. We have radios at 145, 153, and 168MHz on one antenna, and all radios perform the same, no difference in gain was noted. There may be some skewing of the vertical radiation angle at the different frequencies, but we haven't noticed that either. Telewave only makes one model of antenna to cover the whole VHF range. The same antenna is sold to those who use it at 170 as those who use it at 140, and no gain changes are noted in the literature. I'm sure there are differences in the gain, but they are miniscule, certainly nothing major. There are lots of antennas that have gain and wide bandwidth, the two are not mutually exclusive. A Stationmaster and SuperStationmaster look similar, and have similar gain, but the SSM will have 8MHz of bandwidth on VHF compared to less than 2 for the SM. Joe Need a quick answer? Get one in minutes from people who know. Ask your question on www.Answers.yahoo.com
