Re: [Cal_Boats] Antenna placement (Allen)

I did some of that analysis using AREPS 3.0. A few comments - "This difference could be easily made up by more antenna gain with a stern mounted antenna, for example one of the 8 ft whips." As Lee Corso says, not so fast my friend. My initial analysis assumed 6 dB antennas which is what the 8' antennas are. Further, according to AREPS, the additional gain required is 6 dB. So you would need a 12 dB antenna. Now you may be able to find (or build) one, but West doesn't appear to sell one.. Further, since the increased gain is as a result of pattern gain we would be either introducing peaks and nulls into the azimuth pattern, or narrowing the elevation beam. Narrowing the elevation beam is problematic in that, from the side, your signal is pointed either into the air or into the water when the boat is heeled. Fore and aft the heeling results in a polarization shift with part of the energy going into the horizontal plane but at moderate angles of heel, that loss is probably negligible.. My take is, if the range is important to you, go with the masthead mount. If not, or if the increased range does not offset the increased complexity, go with the rail mount. I suspect that the differences are small enough that they can not be validated without a calibrated antenna range and test equipment. We would be trying to measure 170 dB or so of path loss to a 6 dB accuracy. In my experience that's hard, particularly in nature. Al

I love it when you guys talk dirty. I know a fair amount about radios, but the science of radiation is almost obscene. Ahh, the fond memories of messing with the IONCAP model to see if HF users could communicate. Have you ever noticed that when you are driving along in the far boondocks, the only radio stations you can tune in are either country music or religious stations? Gave me the idea that all critical messages should be encoded as country songs. Bound to get through. Cheers Charlie From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Al Waschka Sent: Saturday, January 09, 2010 8:46 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Antenna placement (Allen) I did some of that analysis using AREPS 3.0. A few comments - "This difference could be easily made up by more antenna gain with a stern mounted antenna, for example one of the 8 ft whips." As Lee Corso says, not so fast my friend. My initial analysis assumed 6 dB antennas which is what the 8' antennas are. Further, according to AREPS, the additional gain required is 6 dB. So you would need a 12 dB antenna. Now you may be able to find (or build) one, but West doesn't appear to sell one. Further, since the increased gain is as a result of pattern gain we would be either introducing peaks and nulls into the azimuth pattern, or narrowing the elevation beam. Narrowing the elevation beam is problematic in that, from the side, your signal is pointed either into the air or into the water when the boat is heeled. Fore and aft the heeling results in a polarization shift with part of the energy going into the horizontal plane but at moderate angles of heel, that loss is probably negligible. My take is, if the range is important to you, go with the masthead mount. If not, or if the increased range does not offset the increased complexity, go with the rail mount. I suspect that the differences are small enough that they can not be validated without a calibrated antenna range and test equipment. We would be trying to measure 170 dB or so of path loss to a 6 dB accuracy. In my experience that's hard, particularly in nature. Al

Charlie, I think you've got something there. Al --- On Sat, 1/9/10, Husar, Charlie [USA] <hu… [at] bah.com> wrote: From: Husar, Charlie [USA] <hu… [at] bah.com> Subject: RE: [Cal_Boats] Antenna placement To: "Ca… [at] yahoogroups.com" <Ca… [at] yahoogroups.com> Date: Saturday, January 9, 2010, 9:05 PM I love it when you guys talk dirty. I know a fair amount about radios, but the science of radiation is almost obscene. Ahh, the fond memories of messing with the IONCAP model to see if HF users could communicate. Have you ever noticed that when you are driving along in the far boondocks, the only radio stations you can tune in are either country music or religious stations? Gave me the idea that all critical messages should be encoded as country songs. Bound to get through. Cheers Charlie From: Cal_Boats@yahoogrou ps.com [mailto:Cal_ Boats@yahoogroup s.com] On Behalf Of Al Waschka Sent: Saturday, January 09, 2010 8:46 PM To: Cal_Boats@yahoogrou ps.com Subject: Re: [Cal_Boats] Antenna placement (Allen) I did some of that analysis using AREPS 3.0. A few comments - "This difference could be easily made up by more antenna gain with a stern mounted antenna, for example one of the 8 ft whips." As Lee Corso says, not so fast my friend. My initial analysis assumed 6 dB antennas which is what the 8' antennas are. Further, according to AREPS, the additional gain required is 6 dB. So you would need a 12 dB antenna. Now you may be able to find (or build) one, but West doesn't appear to sell one. Further, since the increased gain is as a result of pattern gain we would be either introducing peaks and nulls into the azimuth pattern, or narrowing the elevation beam. Narrowing the elevation beam is problematic in that, from the side, your signal is pointed either into the air or into the water when the boat is heeled. Fore and aft the heeling results in a polarization shift with part of the energy going into the horizontal plane but at moderate angles of heel, that loss is probably negligible. My take is, if the range is important to you, go with the masthead mount. If not, or if the increased range does not offset the increased complexity, go with the rail mount. I suspect that the differences are small enough that they can not be validated without a calibrated antenna range and test equipment. We would be trying to measure 170 dB or so of path loss to a 6 dB accuracy. In my experience that's hard, particularly in nature. Al

Not so fast yourself. The antenna at the masthead is certainly a 3dB antenna. According to Al Waschka from an earlier post using AREPS, the advantage of the masthead height could be made up by having an extra 3dB on the stern antenna. All I am saying is that I am seeing at least a dB better gain from the lower antenna and over 2dB less loss from the cable so you get the 3DB with the same antenna. The December thread concluded that a 6dB antenna on the stern would give better range than an 3dB antenna on the masthead assuming no cable loss. I am just updating that with the finding of a better pattern from the lower antenna and the lower loss from any real world cable. I was also adding detail on where to mount the stern antenna. Allen On Sat, Jan 9, 2010 at 5:46 PM, Al Waschka <aw… [at] bellsouth.net> wrote: > > > I did some of that analysis using AREPS 3.0. A few comments - > > "This difference could be easily made up by more antenna gain with a stern > mounted antenna, for example one of the 8 ft whips." As Lee Corso says, not > so fast my friend. My initial analysis assumed 6 dB antennas which is what > the 8' antennas are. Further, according to AREPS, the additional gain > required is 6 dB. So you would need a 12 dB antenna. Now you may be able > to find (or build) one, but West doesn't appear to sell one. Further, since > the increased gain is as a result of pattern gain we would be either > introducing peaks and nulls into the azimuth pattern, or narrowing > the elevation beam. Narrowing the elevation beam is problematic in that, > from the side, your signal is pointed either into the air or into the water > when the boat is heeled. Fore and aft the heeling results in a polarization > shift with part of the energy going into the horizontal plane but at > moderate angles of heel, that loss is probably negligible. > > My take is, if the range is important to you, go with the masthead mount. > If not, or if the increased range does not offset the increased complexity, > go with the rail mount. > > I suspect that the differences are small enough that they can not be > validated without a calibrated antenna range and test equipment. We would > be trying to measure 170 dB or so of path loss to a 6 dB accuracy. In my > experience that's hard, particularly in nature. > > Al > > > > >

I know of no sailboats in the south Florida area that has a stern mounted antenna. I suppose they just aren't popular here in this area. Why, I have no idea. We typically use a handheld for ICW navigation and communication with the draw bridges. For our fixed mount VHF, we have a mast head mounted 3db antenna, cabled with hefty (.41 inch diameter) RG-213 coax. I am no RF expert. A friend of mine that is a HAM operator "ran the numbers" for me and said that the RG-213 was the deal breaker and stay away from RG-8X. I took his advise. Magic's Clear & Standing By. --- On Sat, 1/9/10, Husar, Charlie [USA] <hu… [at] bah.com> wrote: From: Husar, Charlie [USA] <hu… [at] bah.com> Subject: RE: [Cal_Boats] Antenna placement To: "Ca… [at] yahoogroups.com" <Ca… [at] yahoogroups.com> Date: Saturday, January 9, 2010, 9:05 PM I love it when you guys talk dirty. I know a fair amount about radios, but the science of radiation is almost obscene. Ahh, the fond memories of messing with the IONCAP model to see if HF users could communicate. Have you ever noticed that when you are driving along in the far boondocks, the only radio stations you can tune in are either country music or religious stations? Gave me the idea that all critical messages should be encoded as country songs. Bound to get through. Cheers Charlie From: Cal_Boats@yahoogrou ps.com [mailto:Cal_ Boats@yahoogroup s.com] On Behalf Of Al Waschka Sent: Saturday, January 09, 2010 8:46 PM To: Cal_Boats@yahoogrou ps.com Subject: Re: [Cal_Boats] Antenna placement (Allen) I did some of that analysis using AREPS 3.0. A few comments - "This difference could be easily made up by more antenna gain with a stern mounted antenna, for example one of the 8 ft whips." As Lee Corso says, not so fast my friend. My initial analysis assumed 6 dB antennas which is what the 8' antennas are. Further, according to AREPS, the additional gain required is 6 dB. So you would need a 12 dB antenna. Now you may be able to find (or build) one, but West doesn't appear to sell one. Further, since the increased gain is as a result of pattern gain we would be either introducing peaks and nulls into the azimuth pattern, or narrowing the elevation beam. Narrowing the elevation beam is problematic in that, from the side, your signal is pointed either into the air or into the water when the boat is heeled. Fore and aft the heeling results in a polarization shift with part of the energy going into the horizontal plane but at moderate angles of heel, that loss is probably negligible. My take is, if the range is important to you, go with the masthead mount. If not, or if the increased range does not offset the increased complexity, go with the rail mount. I suspect that the differences are small enough that they can not be validated without a calibrated antenna range and test equipment. We would be trying to measure 170 dB or so of path loss to a 6 dB accuracy. In my experience that's hard, particularly in nature. Al

The type of coax is important and you got good advice. 50 feet at 156MHz of RG-213 has 1.4dB loss where RG-8x has 2.1dB so you picked up .7dB. RG-58A, which West Marine sells, would cost you 2.9dB. That is the coax that comes with some of the antennas you buy. I am guessing most people do not use RG-213 as it is so big. Use RG-58A and there is no question that you are better off stern mounted, which was my point. 4NEC2 says you pick up 1dB by mounting an antenna at 5ft over water vs at 40ft, so that is the other dB I was assuming. The point from the post late last year was that an 8ft antenna on the stern will beat a 3ft antenna on the mast even ignoring cable loss and pattern differences. By the way, it is important that a masthead antenna be 3ft long (or 8 ft if you really want range). If you use one of the 1.5ft antennas like I see at the marina, all the energy goes up about 20 degrees off of straight up and you will get much less range. Anyway, I see most people use mast mounted antennas and my guess is that this is based on calculations that you get much more range but that the calculations do not take into account transmission over water and cable loss. Just throwing it out there to perhaps same someone the trouble and weight aloft. Again, it would be great to have someone confirm this with a real world test. I can't because I don't have a masthead antenna. It goes against conventional wisdom but that doesn't make it wrong. Full disclosure: I am a HAM and a degreed EE who worked in radio for 30 years but am not an antenna or RF transmission expert. Allen On Sun, Jan 10, 2010 at 5:05 AM, Michael D <md… [at] yahoo.com> wrote: > > > I know of no sailboats in the south Florida area that has a stern mounted > antenna. I suppose they just aren't popular here in this area. Why, I have > no idea. > > We typically use a handheld for ICW navigation and communication with the > draw bridges. For our fixed mount VHF, we have a mast head mounted 3db > antenna, cabled with hefty (.41 inch diameter) RG-213 coax. > > I am no RF expert. A friend of mine that is a HAM operator "ran the > numbers" for me and said that the RG-213 was the deal breaker and stay away > from RG-8X. I took his advise. > > Magic's Clear & Standing By. > > > --- On *Sat, 1/9/10, Husar, Charlie [USA] <hu… [at] bah.com>* wrote: > > > From: Husar, Charlie [USA] <hu… [at] bah.com> > Subject: RE: [Cal_Boats] Antenna placement > To: "Ca… [at] yahoogroups.com" <Ca… [at] yahoogroups.com> > Date: Saturday, January 9, 2010, 9:05 PM > > > > I love it when you guys talk dirty. > > I know a fair amount about radios, but the science of radiation is almost > obscene. Ahh, the fond memories of messing with the IONCAP model to see if > HF users could communicate. > > Have you ever noticed that when you are driving along in the far boondocks, > the only radio stations you can tune in are either country music or > religious stations? Gave me the idea that all critical messages should be > encoded as country songs. Bound to get through. > > Cheers > Charlie > > ------------------------------ > *From:* Cal_Boats@yahoogrou ps.com [mailto:Cal_ Boats@yahoogroup s.com] *On > Behalf Of *Al Waschka > > *Sent:* Saturday, January 09, 2010 8:46 PM > *To:* Cal_Boats@yahoogrou ps.com > > *Subject:* Re: [Cal_Boats] Antenna placement (Allen) > > I did some of that analysis using AREPS 3.0. A few comments - > > "This difference could be easily made up by more antenna gain with a stern > mounted antenna, for example one of the 8 ft whips." As Lee Corso says, not > so fast my friend. My initial analysis assumed 6 dB antennas which is what > the 8' antennas are. Further, according to AREPS, the additional gain > required is 6 dB. So you would need a 12 dB antenna. Now you may be able > to find (or build) one, but West doesn't appear to sell one. Further, since > the increased gain is as a result of pattern gain we would be either > introducing peaks and nulls into the azimuth pattern, or narrowing > the elevation beam. Narrowing the elevation beam is problematic in that, > from the side, your signal is pointed either into the air or into the water > when the boat is heeled. Fore and aft the heeling results in a polarization > shift with part of the energy going into the horizontal plane but at > moderate angles of heel, that loss is probably negligible. > > My take is, if the range is important to you, go with the masthead mount. > If not, or if the increased range does not offset the increased complexity, > go with the rail mount. > > I suspect that the differences are small enough that they can not be > validated without a calibrated antenna range and test equipment. We would > be trying to measure 170 dB or so of path loss to a 6 dB accuracy. In my > experience that's hard, particularly in nature. > > Al > > > > > >

You may be using a 3 dB antenna at the masthead. I am too. But the analysis I ran before assumed a 6 dB antenna in all locations. At least that's what my spreadsheet said when I looked at it the other night. And that's why I said there is a benefit to mounting at the masthead.. BTW I agree with your suggestion on the centerline mount, and I don't disagree with the plan to use a stern mount. If you are considering a 3 dB antenna at the masthead vs. a 6 dB antenna on the rail and fed with the same coax in either case, the the performance will be almost identical, at least according to AREPS. The stern mount antenna has 3 dB more gain and 2 dB less line loss. The analysis I ran the other night indicates that the difference between a 10' ASL antenna and a 50' ASL antenna talking to a either a 10' ASL antenna or a 150" ASL antenna was 6 dB and you have made up 5. Al --- On Sun, 1/10/10, Allen Edwards <al… [at] PaloAltoPhoto.com> wrote: From: Allen Edwards <al… [at] PaloAltoPhoto.com> Subject: Re: [Cal_Boats] Antenna placement (Allen) To: Ca… [at] yahoogroups.com Date: Sunday, January 10, 2010, 2:16 AM Not so fast yourself. The antenna at the masthead is certainly a 3dB antenna. According to Al Waschka from an earlier post using AREPS, the advantage of the masthead height could be made up by having an extra 3dB on the stern antenna. All I am saying is that I am seeing at least a dB better gain from the lower antenna and over 2dB less loss from the cable so you get the 3DB with the same antenna. The December thread concluded that a 6dB antenna on the stern would give better range than an 3dB antenna on the masthead assuming no cable loss. I am just updating that with the finding of a better pattern from the lower antenna and the lower loss from any real world cable. I was also adding detail on where to mount the stern antenna. Allen On Sat, Jan 9, 2010 at 5:46 PM, Al Waschka <awaschka@bellsouth. net> wrote: I did some of that analysis using AREPS 3.0. A few comments - "This difference could be easily made up by more antenna gain with a stern mounted antenna, for example one of the 8 ft whips." As Lee Corso says, not so fast my friend. My initial analysis assumed 6 dB antennas which is what the 8' antennas are. Further, according to AREPS, the additional gain required is 6 dB. So you would need a 12 dB antenna. Now you may be able to find (or build) one, but West doesn't appear to sell one. Further, since the increased gain is as a result of pattern gain we would be either introducing peaks and nulls into the azimuth pattern, or narrowing the elevation beam. Narrowing the elevation beam is problematic in that, from the side, your signal is pointed either into the air or into the water when the boat is heeled. Fore and aft the heeling results in a polarization shift with part of the energy going into the horizontal plane but at moderate angles of heel, that loss is probably negligible. My take is, if the range is important to you, go with the masthead mount. If not, or if the increased range does not offset the increased complexity, go with the rail mount. I suspect that the differences are small enough that they can not be validated without a calibrated antenna range and test equipment. We would be trying to measure 170 dB or so of path loss to a 6 dB accuracy. In my experience that's hard, particularly in nature. Al

Hi, All. Just wanted to drop a note on dBs for the less technically inclined. In power discussion, 3 dB is a factor of two. So a 3 dB loss at a transmitter could be the difference between 12.5 watts and 25 watts of power presented to the antenna. That's a lot. At a receiver, it is still a factor of two, but now we are talking microwatts or less - very small numbers. Here's the rub. If I/they radiate half as much, I/they receive half as much (close enough for discussion) at the receiver. Effect of losses at each end are the same. If I get a radio with a more sensitive. selective receiver, I can get back some of the losses from the remote transmitters. There is some trade-off in cost. Ideally, I would like to optimize both ends, but the improved receiver can help. Keep in mind that the losses discussed here at the transmitter are also experienced at the receiver. For 3 dB loss, we get not only one-half losses in transmit, but also in receive. I will leave out noise figures/reflections related to poor coax and poor install and cheap radios. Good to go with good stuff if you will have a heavy reliance on your radio. Choices, choices. Lesse. New sail or new radio and antenna rig? By the by, dBs are a log 10 scale. For power, 10 dB is a factor of 10. 20 dB is a factor of 100. 30 dB is a factor of 1000. It sure adds up quick. Next time, we can discuss the multiple ways that stereo manufacturers can lie to you about the power output of their products. Cheers Charlie From: Ca… [at] yahoogroups.com [mailto:Ca… [at] yahoogroups.com] On Behalf Of Al Waschka Sent: Sunday, January 10, 2010 10:10 PM To: Ca… [at] yahoogroups.com Subject: Re: [Cal_Boats] Antenna placement (Allen) You may be using a 3 dB antenna at the masthead. I am too. But the analysis I ran before assumed a 6 dB antenna in all locations. At least that's what my spreadsheet said when I looked at it the other night. And that's why I said there is a benefit to mounting at the masthead. BTW I agree with your suggestion on the centerline mount, and I don't disagree with the plan to use a stern mount. If you are considering a 3 dB antenna at the masthead vs. a 6 dB antenna on the rail and fed with the same coax in either case, the the performance will be almost identical, at least according to AREPS. The stern mount antenna has 3 dB more gain and 2 dB less line loss. The analysis I ran the other night indicates that the difference between a 10' ASL antenna and a 50' ASL antenna talking to a either a 10' ASL antenna or a 150" ASL antenna was 6 dB and you have made up 5. Al --- On Sun, 1/10/10, Allen Edwards <al… [at] PaloAltoPhoto.com> wrote: From: Allen Edwards <al… [at] PaloAltoPhoto.com> Subject: Re: [Cal_Boats] Antenna placement (Allen) To: Ca… [at] yahoogroups.com Date: Sunday, January 10, 2010, 2:16 AM Not so fast yourself. The antenna at the masthead is certainly a 3dB antenna. According to Al Waschka from an earlier post using AREPS, the advantage of the masthead height could be made up by having an extra 3dB on the stern antenna. All I am saying is that I am seeing at least a dB better gain from the lower antenna and over 2dB less loss from the cable so you get the 3DB with the same antenna. The December thread concluded that a 6dB antenna on the stern would give better range than an 3dB antenna on the masthead assuming no cable loss. I am just updating that with the finding of a better pattern from the lower antenna and the lower loss from any real world cable. I was also adding detail on where to mount the stern antenna. Allen On Sat, Jan 9, 2010 at 5:46 PM, Al Waschka <awaschka@bellsouth. net<http://us.mc1806.mail.yahoo.com/mc/compose?to=aw… [at] bellsouth.net>> wrote: I did some of that analysis using AREPS 3.0. A few comments - "This difference could be easily made up by more antenna gain with a stern mounted antenna, for example one of the 8 ft whips." As Lee Corso says, not so fast my friend. My initial analysis assumed 6 dB antennas which is what the 8' antennas are. Further, according to AREPS, the additional gain required is 6 dB. So you would need a 12 dB antenna. Now you may be able to find (or build) one, but West doesn't appear to sell one. Further, since the increased gain is as a result of pattern gain we would be either introducing peaks and nulls into the azimuth pattern, or narrowing the elevation beam. Narrowing the elevation beam is problematic in that, from the side, your signal is pointed either into the air or into the water when the boat is heeled. Fore and aft the heeling results in a polarization shift with part of the energy going into the horizontal plane but at moderate angles of heel, that loss is probably negligible. My take is, if the range is important to you, go with the masthead mount. If not, or if the increased range does not offset the increased complexity, go with the rail mount. I suspect that the differences are small enough that they can not be validated without a calibrated antenna range and test equipment. We would be trying to measure 170 dB or so of path loss to a 6 dB accuracy. In my experience that's hard, particularly in nature. Al

Thanks for clarifying what you did with your spreadsheet. I think I was double counting the cable loss. What I am taking away from this clarification is that the mast mount antenna is 6dB better than the stern one. In practice you cannot gain all of that advantage because of other factors. Everyone agrees on the 2dB from line loss so that leaves 4dB. An 8ft antenna will make most of that up. But is there a way to make some of that up with a 3ft antenna. I am seeing better patterns with an antenna closer to the water and a slight improvement by eliminating the mast under the antenna. I am having trouble quantifying that. I do think some of the 4dB, if not all, is made up though. Perhaps that is already in the AREPS program though so I might be double counting again. Anyway, I continue to not want the weight aloft and want the antenna to work its best if I am dismasted so remain a fan of stern mounted antennas even if I might need more TX power. As all I want to do is hear the committee boat, I am happy with what I have. If I wanted more range I would put up the 8ft antenna as I have about 6 of them brand new in my garage that I inherited and have never used. Allen On Sun, Jan 10, 2010 at 7:10 PM, Al Waschka <aw… [at] bellsouth.net> wrote: > > > You may be using a 3 dB antenna at the masthead. I am too. But the > analysis I ran before assumed a 6 dB antenna in all locations. At least > that's what my spreadsheet said when I looked at it the other night. And > that's why I said there is a benefit to mounting at the masthead. > > BTW I agree with your suggestion on the centerline mount, and I don't > disagree with the plan to use a stern mount. If you are considering a 3 dB > antenna at the masthead vs. a 6 dB antenna on the rail and fed with the same > coax in either case, the the performance will be almost identical, at least > according to AREPS. The stern mount antenna has 3 dB more gain and 2 dB > less line loss. The analysis I ran the other night indicates that the > difference between a 10' ASL antenna and a 50' ASL antenna talking to a > either a 10' ASL antenna or a 150" ASL antenna was 6 dB and you have made up > 5. > > Al > > > --- On *Sun, 1/10/10, Allen Edwards <al… [at] PaloAltoPhoto.com>*wrote: > > > From: Allen Edwards <al… [at] PaloAltoPhoto.com> > Subject: Re: [Cal_Boats] Antenna placement (Allen) > To: Ca… [at] yahoogroups.com > Date: Sunday, January 10, 2010, 2:16 AM > > > Not so fast yourself. The antenna at the masthead is certainly a 3dB > antenna. According to Al Waschka from an earlier post using AREPS, the > advantage of the masthead height could be made up by having an extra 3dB on > the stern antenna. All I am saying is that I am seeing at least a dB better > gain from the lower antenna and over 2dB less loss from the cable so you get > the 3DB with the same antenna. > > The December thread concluded that a 6dB antenna on the stern would give > better range than an 3dB antenna on the masthead assuming no cable loss. I > am just updating that with the finding of a better pattern from the lower > antenna and the lower loss from any real world cable. > > I was also adding detail on where to mount the stern antenna. > > Allen > > > > On Sat, Jan 9, 2010 at 5:46 PM, Al Waschka <awaschka@bellsouth. net<http://us.mc1806.mail.yahoo.com/mc/compose?to=aw… [at] bellsouth.net> > > wrote: > >> >> I did some of that analysis using AREPS 3.0. A few comments - >> >> "This difference could be easily made up by more antenna gain with a stern >> mounted antenna, for example one of the 8 ft whips." As Lee Corso says, not >> so fast my friend. My initial analysis assumed 6 dB antennas which is what >> the 8' antennas are. Further, according to AREPS, the additional gain >> required is 6 dB. So you would need a 12 dB antenna. Now you may be able >> to find (or build) one, but West doesn't appear to sell one. Further, since >> the increased gain is as a result of pattern gain we would be either >> introducing peaks and nulls into the azimuth pattern, or narrowing >> the elevation beam. Narrowing the elevation beam is problematic in that, >> from the side, your signal is pointed either into the air or into the water >> when the boat is heeled. Fore and aft the heeling results in a polarization >> shift with part of the energy going into the horizontal plane but at >> moderate angles of heel, that loss is probably negligible. >> >> My take is, if the range is important to you, go with the masthead mount. >> If not, or if the increased range does not offset the increased complexity, >> go with the rail mount. >> >> I suspect that the differences are small enough that they can not be >> validated without a calibrated antenna range and test equipment. We would >> be trying to measure 170 dB or so of path loss to a 6 dB accuracy. In my >> experience that's hard, particularly in nature. >> >> Al >> >> >> > > >

Husar, Charlie [USA] wrote: > > > Have you ever noticed that when you are driving along in the far > boondocks, the only radio stations you can tune in are either country > music or religious stations? I've got a 1922 Crosley two-tube regenerative radio receiver, a very early commercial home radio that in its day was operated off three sets of batteries. I bought a power supply and hooked the thing up to my long-wire backyard antenna. I received the two local AM radio stations, of course, and one other--WSM from Nashville (think Grand Ole Opry). The radio gods had obviously figured out that I wasn't a good candidate for religious messages. Chris Campbell

Hello All, We did the Fort Lauderdale to Key West race last week. Brenda and I crewed on Sempre Amantes, a 42 foot Hunter Passage. We finished elapsed time of 23:57:08 hours and took 5th place. Here are some photos of the race and time spent in Key West. Crosswinds, a Corsair F-27 Formula, hit the reef, took on water, and had to be towed into Marathon. Fortunately, no one was hurt. Scoring for the race can be seen here. Regards, Michael