Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz?
That might be true, but your original implication stated that changing the element spacing was done to get downtilt; which is not possible. Your original implication also said nothing about the harness which would lead others to believe that the only thing needed to obtain downtilt on a DB-224 was to change the element spacing; which is totally incorrect and physically not possible. Kevin Custer russ wrote: True but when you change the harness to get down tilt (PER DB) you also change the spacing. (Also per DB) . 73 Russ, russ wrote: Hey every one, Let us not forget that they change the spacing to get down till on the DB-224. Wrong. The only way to get downtilt on a binary fed exposed dipole array is to either build the phasing harness so the electrical length feeding each element is slightly longer in phase with respect to the one next to it, or mechanically tilt the array if it is a cardiod pattern. Varying spacing between elements has little effect on the vertical beam pattern. There is very little difference in the performance of a dipole array with varying amounts of spacing between the elements. Most manufacturers shoot for about 80 to 90% of a full wavelength between elements, but the spacing is really not that critical. Also, the amount of pipe above the top element is not critical as long as there is enough to maintain the impedance of that element. It could be 2 inches or 2 feet, as long as the match is okay it doesn't matter. The spacing of the element from the mast (reflector) affects impedance greatly. Don't try to mount your Cushcraft AFM-4DA or 44DA on a fiberglass or plastic mast pipe. It won't work Kevin Custer Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz?
When I converted my 224 to VHF amateur band, the element length went from 35 inches (150mhz unit) to 37 inches (144mhz). The spacing on the elements was somewhat limited by the new harness length. Had to work with it a good bit to get somewhat equal spacing on the pole. Had to lengthen the pole some also to get the clams down and away from the elements. I did the double cut on both ends and inserted a smaller tube inside the orginal. Tig Welded them back 100%. Been playing fine for 4 years. --- In Repeater-Builder@yahoogroups.com, kf0m [EMAIL PROTECTED] wrote: If you look back at a post I did a couple of days ago The variable element to element spacing on our DB224E's new from the factory ran anywhere from 62 to 70 inches. If you do some web searches there are several methods that have been used to extend the short elements. These range from cutting the elements and making a trombone slide arrangement, to inserting a screw in the ends, to using long hose clamps and letting tails stick out the right length. We happened to be fortunate enough to have a welder in the club and he welded short stubs of aluminum tubing on the ends of each 35 inch element to extend them out to the 37 inch dimension. John Lock KF0M Wichita KS kf0m at arrl dot net Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
Kevin is quite correct. Tis the phasing harness construction that determines downtilt of a corporate feed antenna (or physical tilt of the antenna). Chuck WB2EDV - Original Message - From: Kevin Custer [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, January 24, 2005 5:46 PM Subject: Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? russ wrote: Hey every one, Let us not forget that they change the spacing to get down till on the DB-224. Wrong. The only way to get downtilt on a binary fed exposed dipole array is to either build the phasing harness so the electrical length feeding each element is slightly longer in phase with respect to the one next to it, or mechanically tilt the array if it is a cardiod pattern. Varying spacing between elements has little effect on the vertical beam pattern. There is very little difference in the performance of a dipole array with varying amounts of spacing between the elements. Most manufacturers shoot for about 80 to 90% of a full wavelength between elements, but the spacing is really not that critical. Also, the amount of pipe above the top element is not critical as long as there is enough to maintain the impedance of that element. It could be 2 inches or 2 feet, as long as the match is okay it doesn't matter. The spacing of the element from the mast (reflector) affects impedance greatly. Don't try to mount your Cushcraft AFM-4DA or 44DA on a fiberglass or plastic mast pipe. It won't work Kevin Custer Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
There is a model folded dipole I saw for 30 megs that had tunable rods at the top of the loops. It had a set screw an could be field adjusted. But then this is lowband and it was more to save weight and make the antenna tunable across more of the band. Kevin King SCSA BSCIS ARS KC6OVD GMRS KAG0378 EIEIO 2722 Acworth Georgia -Original Message- From: Chuck Kelsey [mailto:[EMAIL PROTECTED] Sent: Monday, January 24, 2005 6:46 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? Mike's suggestion is the best method and the one I would choose. I would suspect that this would be the method used by a ham that has no problem drilling a hole in his car to mount a mobile antenna. On the other hand, I'd be willing to bet that the extend the element with a bolt crowd is the same group that uses a mag mount mobile antenna. Just an observation. You may disagree. Chuck WB2EDV - Original Message - From: Mike Morris WA6ILQ [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, January 24, 2005 12:20 AM Subject: Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? At 04:29 PM 1/23/05, you wrote: I have seen the screw in the ends modification and am leaning in that direction. But they need to be well sealed I am sure to prevent corrosion and the associated noise that can be produced. I understand that the element to the support contact needs to be welded also to remove that intermittent connection and the possibility of corrosion causing noise if used in repeater service. Russ N4KOX I've also seen a DB224 that was modified by a ham. He cut the elements just inside the curve and spliced in tubing (that was picked so that the inside diameter just fit the outside diameter of the element) to stretch the element. Four elements times two upper and two lower cuts = 16 new joints. He used hacksaw cuts tubing and stainless steel hose clamps to verify the lengths. After the test was done the antenna was took back down and everything welded. The modified antenna was coupled with a new harness made for 2m and the combination outperformed anything else at that site. Mike WA6ILQ Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
Correct. Phelps Dodge did this on their VHF low-band antennas only. I'm not saying that drilling a hole at the ends of the loops and adding a bolt to extend them won't work. I'm saying that actually extending the loop is a better choice form a mechanical standpoint. Chuck WB2EDV - Original Message - From: Kevin King [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, January 24, 2005 10:29 PM Subject: RE: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? There is a model folded dipole I saw for 30 megs that had tunable rods at the top of the loops. It had a set screw an could be field adjusted. But then this is lowband and it was more to save weight and make the antenna tunable across more of the band. Kevin King SCSA BSCIS ARS KC6OVD GMRS KAG0378 EIEIO 2722 Acworth Georgia -Original Message- From: Chuck Kelsey [mailto:[EMAIL PROTECTED] Sent: Monday, January 24, 2005 6:46 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? Mike's suggestion is the best method and the one I would choose. I would suspect that this would be the method used by a ham that has no problem drilling a hole in his car to mount a mobile antenna. On the other hand, I'd be willing to bet that the extend the element with a bolt crowd is the same group that uses a mag mount mobile antenna. Just an observation. You may disagree. Chuck WB2EDV - Original Message - From: Mike Morris WA6ILQ [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, January 24, 2005 12:20 AM Subject: Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? At 04:29 PM 1/23/05, you wrote: I have seen the screw in the ends modification and am leaning in that direction. But they need to be well sealed I am sure to prevent corrosion and the associated noise that can be produced. I understand that the element to the support contact needs to be welded also to remove that intermittent connection and the possibility of corrosion causing noise if used in repeater service. Russ N4KOX I've also seen a DB224 that was modified by a ham. He cut the elements just inside the curve and spliced in tubing (that was picked so that the inside diameter just fit the outside diameter of the element) to stretch the element. Four elements times two upper and two lower cuts = 16 new joints. He used hacksaw cuts tubing and stainless steel hose clamps to verify the lengths. After the test was done the antenna was took back down and everything welded. The modified antenna was coupled with a new harness made for 2m and the combination outperformed anything else at that site. Mike WA6ILQ Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
True but when you change the harness to get down tilt (PER DB) you also change the spacing. (Also per DB) . It is also just cheaper to buy a new DB-224 for the two meter Ham band. You get a new antenna and it will work for many years. Lord knows they are cheaper then grits. 73 Russ, - Original Message - From: Kevin Custer [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, January 24, 2005 5:46 PM Subject: Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? russ wrote: Hey every one, Let us not forget that they change the spacing to get down till on the DB-224. Wrong. The only way to get downtilt on a binary fed exposed dipole array is to either build the phasing harness so the electrical length feeding each element is slightly longer in phase with respect to the one next to it, or mechanically tilt the array if it is a cardiod pattern. Varying spacing between elements has little effect on the vertical beam pattern. There is very little difference in the performance of a dipole array with varying amounts of spacing between the elements. Most manufacturers shoot for about 80 to 90% of a full wavelength between elements, but the spacing is really not that critical. Also, the amount of pipe above the top element is not critical as long as there is enough to maintain the impedance of that element. It could be 2 inches or 2 feet, as long as the match is okay it doesn't matter. The spacing of the element from the mast (reflector) affects impedance greatly. Don't try to mount your Cushcraft AFM-4DA or 44DA on a fiberglass or plastic mast pipe. It won't work Kevin Custer Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
This is also why you get different spacing on the dipoles. It also depends what year in time your harness was made. Over the years they changed coax with new owners (of DB) and that also has a spacing change. Be careful. If you are and do it right you will not have to buy a new DB-224. If not you can go nuts chasseing your tail. Dean Westbrook, EE,PE. Cook Towers, INC. Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz?
Hi all I've followed this thread with great interest seeing that our club just purchased a DB224E to replace an aged stationmaster. Question...We ordered the 138-150 mHz model, Tessco part # 62446. There was nothing in the paperwork referencing element spacing or anything else along those lines. Just info about pattern adjustment. I told the Tessco rep our frequency, 146.730, and he said there is nothing to tune or do to the antenna...just set it and forget it. I do realize that some of the comments during this discussion have been related to other models of the DB224, however, I fell compelled to ask if there is anything we should do to our antenna prior to installing it (will be checking all the bolts and nuts of course). Does the other thread that discussed the element spacing apply to my model? Thanks a bunch in advance Bob, GMRS WPVV845, Amateur KG4WAD, LMRS WPXC892 Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
Well we all deal with Tessco but when you deal with the large box house you get NO consumer service. And no tech support. Yes you could have ordered your 224 from Tessco tuned for your transmit but you would have had to wait for it. Good luck! Dean, Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
RE: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz?
I agree, I took and antenna up and down a temporary tower many of times before placing in on an 85' tower for permanent installation. Helps to have a hazer on a tower to work with. Makes it nice. Mathew -Original Message- From: Chuck Kelsey [mailto:[EMAIL PROTECTED] Sent: Tuesday, January 25, 2005 9:01 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? The thread concerns taking an out of band antenna down to the ham portion of the band - necessitating a new harness and different spacing. If yours is for the correct range, it's ready to inspect and put up. Never hurts to go over everything before taking it up in the air. Chuck WB2EDV - Original Message - From: rtoplus [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, January 25, 2005 8:55 AM Subject: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? Hi all I've followed this thread with great interest seeing that our club just purchased a DB224E to replace an aged stationmaster. Question...We ordered the 138-150 mHz model, Tessco part # 62446. There was nothing in the paperwork referencing element spacing or anything else along those lines. Just info about pattern adjustment. I told the Tessco rep our frequency, 146.730, and he said there is nothing to tune or do to the antenna...just set it and forget it. I do realize that some of the comments during this discussion have been related to other models of the DB224, however, I fell compelled to ask if there is anything we should do to our antenna prior to installing it (will be checking all the bolts and nuts of course). Does the other thread that discussed the element spacing apply to my model? Thanks a bunch in advance Bob, GMRS WPVV845, Amateur KG4WAD, LMRS WPXC892 Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
The thread concerns taking an out of band antenna down to the ham portion of the band - necessitating a new harness and different spacing. If yours is for the correct range, it's ready to inspect and put up. Never hurts to go over everything before taking it up in the air. Chuck WB2EDV - Original Message - From: rtoplus [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Tuesday, January 25, 2005 8:55 AM Subject: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? Hi all I've followed this thread with great interest seeing that our club just purchased a DB224E to replace an aged stationmaster. Question...We ordered the 138-150 mHz model, Tessco part # 62446. There was nothing in the paperwork referencing element spacing or anything else along those lines. Just info about pattern adjustment. I told the Tessco rep our frequency, 146.730, and he said there is nothing to tune or do to the antenna...just set it and forget it. I do realize that some of the comments during this discussion have been related to other models of the DB224, however, I fell compelled to ask if there is anything we should do to our antenna prior to installing it (will be checking all the bolts and nuts of course). Does the other thread that discussed the element spacing apply to my model? Thanks a bunch in advance Bob, GMRS WPVV845, Amateur KG4WAD, LMRS WPXC892 Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
At 05:55 AM 1/25/05, you wrote: Hi all I've followed this thread with great interest seeing that our club just purchased a DB224E to replace an aged stationmaster. Question...We ordered the 138-150 mHz model, Tessco part # 62446. Tessco is a out of sight, out of mind organization. They do not know what the phrase after-sale customer service means. There was nothing in the paperwork referencing element spacing or anything else along those lines. Yup. They pulled a box off the shelf and shipped it. Contact the factory and ask for a mounting diagram / spacing chart. Just info about pattern adjustment. Please go to this web page: http://www.repeater-builder.com/rbtip/ant-sys-index.html Then scroll down to Antennas then DB and if you have anything that isn't there already I'd like to get a copy. I told the Tessco rep our frequency, 146.730, and he said there is nothing to tune or do to the antenna...just set it It's the set it that is the critical part here. and forget it. That's true. I do realize that some of the comments during this discussion have been related to other models of the DB224, Yup. The person who started the thread is converting a commercial range antenna down to the ham band. He's going to need to stretch the elements and get a new harness, and at that point he'll have what you have. however, I fell compelled to ask if there is anything we should do to our antenna prior to installing it (will be checking all the bolts and nuts of course). Buy a tube of Locktite and use it liberally after the nuts and bolts are tight. Does the other thread that discussed the element spacing apply to my model? Yep. Get a factory spacing chart and use it. Are you going to side mount it or top mount it? If on the side, then the distance to the tower is very important as it will control your pattern. And if you side mount it and you have ANY appreciable wind or ice then GET A TOP BRACE MADE FOR THE JOB and use it. Thanks a bunch in advance Bob, GMRS WPVV845, Amateur KG4WAD, LMRS WPXC892 Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
Thanks all for the infowipes nervous perspiration drops off brow I thought it would be fine, but I wanted to make sure. We will be side mounting the antenna so I will be ordering the DB5001 mounting kit. 73 Bob, GMRS WPVV845, Amateur KG4WAD, LMRS WPXC892 Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
I have seen the screw in the ends modification and am leaning in that direction. But they need to be well sealed I am sure to prevent corrosion and the associated noise that can be produced. I understand that the element to the support contact needs to be welded also to remove that intermittent connection and the possibility of corrosion causing noise if used in repeater service. Russ N4KOX --- In Repeater-Builder@yahoogroups.com, kf0m [EMAIL PROTECTED] wrote: If you look back at a post I did a couple of days ago The variable element to element spacing on our DB224E's new from the factory ran anywhere from 62 to 70 inches. If you do some web searches there are several methods that have been used to extend the short elements. These range from cutting the elements and making a trombone slide arrangement, to inserting a screw in the ends, to using long hose clamps and letting tails stick out the right length. We happened to be fortunate enough to have a welder in the club and he welded short stubs of aluminum tubing on the ends of each 35 inch element to extend them out to the 37 inch dimension. John Lock KF0M Wichita KS kf0m at arrl dot net Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
The distance from the top of the pole to the top dipole is not critical and could easily be moved up to get more room down below for more spacing. The dipoles need to work up against the pole for proper impedance but if the top of the top dipole is 3-4 down that should be OK. If you still run out of room at the bottom, the bottom dipole can be in the clamp area if it faces away from the clamps. Laryn K8TVZ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
To bad that both of the guys that had the most to do with the design of these two antennas are either semi-retired or retired and neither one are Hams. Wouldn't it be great if they were? Paul -Original Message- From: Laryn Lohman [mailto:[EMAIL PROTECTED] Sent: Sunday, January 23, 2005 9:00 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? The distance from the top of the pole to the top dipole is not critical and could easily be moved up to get more room down below for more spacing. The dipoles need to work up against the pole for proper impedance but if the top of the top dipole is 3-4 down that should be OK. If you still run out of room at the bottom, the bottom dipole can be in the clamp area if it faces away from the clamps. Laryn K8TVZ Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
Mike's suggestion is the best method and the one I would choose. I would suspect that this would be the method used by a ham that has no problem drilling a hole in his car to mount a mobile antenna. On the other hand, I'd be willing to bet that the extend the element with a bolt crowd is the same group that uses a mag mount mobile antenna. Just an observation. You may disagree. Chuck WB2EDV - Original Message - From: Mike Morris WA6ILQ [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Monday, January 24, 2005 12:20 AM Subject: Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? At 04:29 PM 1/23/05, you wrote: I have seen the screw in the ends modification and am leaning in that direction. But they need to be well sealed I am sure to prevent corrosion and the associated noise that can be produced. I understand that the element to the support contact needs to be welded also to remove that intermittent connection and the possibility of corrosion causing noise if used in repeater service. Russ N4KOX I've also seen a DB224 that was modified by a ham. He cut the elements just inside the curve and spliced in tubing (that was picked so that the inside diameter just fit the outside diameter of the element) to stretch the element. Four elements times two upper and two lower cuts = 16 new joints. He used hacksaw cuts tubing and stainless steel hose clamps to verify the lengths. After the test was done the antenna was took back down and everything welded. The modified antenna was coupled with a new harness made for 2m and the combination outperformed anything else at that site. Mike WA6ILQ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
Hello All, Do not count on this info being right. The top needs to be right from the top of the mast support pipe to the 1st dipole and then center to center on each after. If the support pipe is not long enough get a longer one. They come in different lengths one for 222 is shorter then one for 174 and one for 144 is longer then the support pile for 174. I have noted this in our warehouse when they are side by side. Here at work we take a DB-224 in band and tune it to the frequency need by the user and everything on this antenna matters so be mindful when you tune or covert one. Matthew is correct after you change the dipoles for Ham uses from the 150 range you must change the harness to make it play right. Oh it will work but not as well as it could. Like someone said this morning on the list. There are people who use mag mounts and tell you how great they work. BIG GRIN! Dean Westbrook, EE,PE Cook Towers, INC. Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz?
Part of the different's is between the harness. Different'sin factors in the coax used. That is why we have to watch out here at work when repairing DB-224's. Be careful. Over the years and with change of ownership DB has made changes along the way. Dean Westbrook, EE,PE. Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz?
At 04:29 PM 1/23/05, you wrote: I have seen the screw in the ends modification and am leaning in that direction. But they need to be well sealed I am sure to prevent corrosion and the associated noise that can be produced. I understand that the element to the support contact needs to be welded also to remove that intermittent connection and the possibility of corrosion causing noise if used in repeater service. Russ N4KOX I've also seen a DB224 that was modified by a ham. He cut the elements just inside the curve and spliced in tubing (that was picked so that the inside diameter just fit the outside diameter of the element) to stretch the element. Four elements times two upper and two lower cuts = 16 new joints. He used hacksaw cuts tubing and stainless steel hose clamps to verify the lengths. After the test was done the antenna was took back down and everything welded. The modified antenna was coupled with a new harness made for 2m and the combination outperformed anything else at that site. Mike WA6ILQ Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
I will have to agree with Dean on this one. I took the DB-224 as it sat with the changed elements, old 150-160 harness, put the antenna up 60 in the air, and it was out performed by 20 to 25 miles against a Diamond XNH-510 Dual Band Antenna. Impedance if I remember right was somewhere near the 80s. VSWR was right about 1.6:1. And I agree with the mag mounts, the family thinks I am nuts for popping two holes right in the truck of my Cadillac. When I get done with the car, for $11.00 a piece Ill just leave the mounts and cut the coax. Mathew From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Monday, January 24, 2005 5:44 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? Hello All, Do not count on this info being right. The top needs to be right from the top of the mast support pipe to the 1st dipole and then center to center on each after. If the support pipe is not long enough get a longer one. They come in different lengths one for 222 is shorter then one for 174 and one for 144 is longer then the support pile for 174. I have noted this in our warehouse when they are side by side. Here at work we take a DB-224 in band and tune it to the frequency need by the user and everything on this antenna matters so be mindful when you tune or covert one. Matthew is correct after you change the dipoles for Ham uses from the 150 range you must change the harness to make it play right. Oh it will work but not as well as it could. Like someone said this morning on the list. There are people who use mag mounts and tell you how great they work. BIG GRIN! Dean Westbrook, EE,PE Cook Towers, INC. Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
RE: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz?
Gee wonder if I can get him to do that on my DB-304, that would be nice. A one of those days projects. Hamfest days. But I have seen one of these done about the same way, and has had no problems with it since it went into service. Should have been a machinest. Mathew -Original Message- From: Mike Morris WA6ILQ [mailto:[EMAIL PROTECTED] Sent: Monday, January 24, 2005 6:17 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? At 03:46 AM 1/24/05, you wrote: Mike's suggestion is the best method and the one I would choose. I would suspect that this would be the method used by a ham that has no problem drilling a hole in his car to mount a mobile antenna. On the other hand, I'd be willing to bet that the extend the element with a bolt crowd is the same group that uses a mag mount mobile antenna. Just an observation. You may disagree. Chuck WB2EDV Thanks for the vote of confidence, Chuck. To elaborate slightly and to correct what I wrote. I've also seen a DB224 that was modified by a ham. He cut the elements just inside the curve and spliced in tubing I should have said in the middle of the straight section above the curve. The modified antenna had the larger diameter tubing bridging the gap in the element, and you obviously can't do that if you've hacksawed the element in the straight section right above the curve. He used hacksaw cuts tubing and stainless steel hose clamps to verify the lengths. I meant to type He used a hacksaw to make the cuts in the tubing and stainless steel hose clamps to verify the lengths. It was a Sawzall with the finest-tooth hacksaw blade he could find. Mike WA6ILQ Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
Hey every one, Let us not forget that they change the spacing to get down till on the DB-224. Also Dean does this stuff every day. The old saying you can't beat a person at there own game mite apply here. 73 Russ, W3CH - Original Message - From: highlandfl [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 23, 2005 6:05 PM Subject: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? I just measured mine (not as cold in North Florida as for you guys, but it was interesting to measure the deminsions on my two antennas: Both Had top element center 26 from top of pipe (so that was OK.) Both had 34.25 inch loops (top to bottom)(reasonable) Both had 62 separations from center of mount for each loop to the next (unexpected.) I was concerned that I would not have enough separation between elements - looks like I have plenty. It really surprised me that my spacing was more than the spacing for 2 meters, escpecially since the elements are much smaller than the 37 that John has and Mathew's given dimension and Cook towers confirmation of 35.25. Interesting. Russ N4KOX --- In Repeater-Builder@yahoogroups.com, kf0m [EMAIL PROTECTED] wrote: If you are looking for the length of the loops in addition to the spacing the 2 meter DB224's I just put up had 37 inch loops on a 22 ft mast. The factory element spacing was not consistent so you should definitely check your spacing per the dimensions Russ gave. I have one 150 mhz DB224 and it has 35 inch loops on an 18 ft mast. Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
russ wrote: Hey every one, Let us not forget that they change the spacing to get down till on the DB-224. Wrong. The only way to get downtilt on a binary fed exposed dipole array is to either build the phasing harness so the electrical length feeding each element is slightly longer in phase with respect to the one next to it, or mechanically tilt the array if it is a cardiod pattern. Varying spacing between elements has little effect on the vertical beam pattern. There is very little difference in the performance of a dipole array with varying amounts of spacing between the elements. Most manufacturers shoot for about 80 to 90% of a full wavelength between elements, but the spacing is really not that critical. Also, the amount of pipe above the top element is not critical as long as there is enough to maintain the impedance of that element. It could be 2 inches or 2 feet, as long as the match is okay it doesn't matter. The spacing of the element from the mast (reflector) affects impedance greatly. Don't try to mount your Cushcraft AFM-4DA or 44DA on a fiberglass or plastic mast pipe. It won't work Kevin Custer Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
Well I am not so sure on that one just yet. Was told that the first element was 26 from the top, and each element was 58 1/4 center to center from there, and if that is true, then I'm going to end up with my last element down into the clamp area. I've been sick most of this week, so have not really messed with it. Hopefully Tuesday I will be feeling better and will be able to get the harness on the antenna then. Mathew Thank you, Mathew. I had been following the discussion of element spacing. Now I need to measure my spacing to see if it is in the right range - I suspect not. What was the spacing that you determined was correct for yours? Russ N4KOX --- In Repeater-Builder@yahoogroups.com, Mathew Quaife [EMAIL PROTECTED] wrote: They are 35 1/4 from top to bottom of the element. You will also need to change the phasing harness. I have one here that had the elements changed, but did not have the harness change, impedance was way out of wack. I just ordered a new harness from Cook Towers, getting ready to install it. Mathew I need to mesaure the DB224 I have for use at 145.11 Mhz. and modify as necessary. Someone had given me the 2 meter loop length but I can not locate it. Anyone know what it should be? or the range for Amateur 2 Meters vs. commercial 150+? Thanks a lot for your help. Russ N4KOX Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
This is 100% correct right of the DB chart. You will be just fine if you set your DB-224 up this way! Dean Westbrook, EE,PE. Cook Towers, INC. Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz?
It is 28" from the top of the pipe not from the end cap on the top of the antenna. Dean, Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
RE: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz?
Thanks Dean, but will the bottom element end up into the mounting section of the antenna, at least half of it? Mathew From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Sunday, January 23, 2005 2:21 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? This is 100% correct right of the DB chart. You will be just fine if you set your DB-224 up this way! Dean Westbrook, EE,PE. Cook Towers, INC. Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
RE: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz?
Ok, was given 26, might have wrote it down wrong. Thanks for clearing that one up. Mathew From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Sent: Sunday, January 23, 2005 2:22 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? It is 28 from the top of the pipe not from the end cap on the top of the antenna. Dean, Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz?
Thanks, I hope you feel better soon. Russ N4KOX --- In Repeater-Builder@yahoogroups.com, Mathew Quaife [EMAIL PROTECTED] wrote: Well I am not so sure on that one just yet. Was told that the first element was 26 from the top, and each element was 58 1/4 center to center from there, and if that is true, then I'm going to end up with my last element down into the clamp area. I've been sick most of this week, so have not really messed with it. Hopefully Tuesday I will be feeling better and will be able to get the harness on the antenna then. Mathew Thank you, Mathew. I had been following the discussion of element spacing. Now I need to measure my spacing to see if it is in the right range - I suspect not. What was the spacing that you determined was correct for yours? Russ N4KOX --- In Repeater-Builder@yahoogroups.com, Mathew Quaife [EMAIL PROTECTED] wrote: They are 35 1/4 from top to bottom of the element. You will also need to change the phasing harness. I have one here that had the elements changed, but did not have the harness change, impedance was way out of wack. I just ordered a new harness from Cook Towers, getting ready to install it. Mathew I need to mesaure the DB224 I have for use at 145.11 Mhz. and modify as necessary. Someone had given me the 2 meter loop length but I can not locate it. Anyone know what it should be? or the range for Amateur 2 Meters vs. commercial 150+? Thanks a lot for your help. Russ N4KOX Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
Hey Mathew, This is how we set up our DB-224 in Ocean City NJ and it works real well. But come down 26 from the top of the pipe and not the point on the end cap. If you do it will through you off all the way down. No the last dipole will NOT hang off the end of the support pipe unless the support pipe is the wrong one. Sounds like you will have fun when the weather breaks. 73 Russ, W3CH - Original Message - From: Mathew Quaife [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Sunday, January 23, 2005 5:08 PM Subject: RE: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? Well I am not so sure on that one just yet. Was told that the first element was 26 from the top, and each element was 58 1/4 center to center from there, and if that is true, then I'm going to end up with my last element down into the clamp area. I've been sick most of this week, so have not really messed with it. Hopefully Tuesday I will be feeling better and will be able to get the harness on the antenna then. Mathew Thank you, Mathew. I had been following the discussion of element spacing. Now I need to measure my spacing to see if it is in the right range - I suspect not. What was the spacing that you determined was correct for yours? Russ N4KOX --- In Repeater-Builder@yahoogroups.com, Mathew Quaife [EMAIL PROTECTED] wrote: They are 35 1/4 from top to bottom of the element. You will also need to change the phasing harness. I have one here that had the elements changed, but did not have the harness change, impedance was way out of wack. I just ordered a new harness from Cook Towers, getting ready to install it. Mathew I need to mesaure the DB224 I have for use at 145.11 Mhz. and modify as necessary. Someone had given me the 2 meter loop length but I can not locate it. Anyone know what it should be? or the range for Amateur 2 Meters vs. commercial 150+? Thanks a lot for your help. Russ N4KOX Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
Oh indeed, will give it a shot and see what happens, hate to mess it up since I have to redrill the holes for the new harness. As for fun when the weather breaks, you bet, a 100' Self Support Pyrod to install, at least 4 other towers for GMRS and the repeater, all over 100'. Sounds like a busy spring and summer for me. Then my buddy is installing a 100' tower. Got lots to do and little time to get it all done in. Thanks Russ. Mathew Hey Mathew, This is how we set up our DB-224 in Ocean City NJ and it works real well. But come down 26 from the top of the pipe and not the point on the end cap. If you do it will through you off all the way down. No the last dipole will NOT hang off the end of the support pipe unless the support pipe is the wrong one. Sounds like you will have fun when the weather breaks. 73 Russ, W3CH Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
If you are looking for the length of the loops in addition to the spacing the 2 meter DB224's I just put up had 37 inch loops on a 22 ft mast. The factory element spacing was not consistent so you should definitely check your spacing per the dimensions Russ gave. I have one 150 mhz DB224 and it has 35 inch loops on an 18 ft mast. John Lock KF0M Wichita KS kf0m at arrl dot net -Original Message- From: Mathew Quaife [mailto:[EMAIL PROTECTED] Sent: Sunday, January 23, 2005 4:08 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? Well I am not so sure on that one just yet. Was told that the first element was 26 from the top, and each element was 58 1/4 center to center from there, and if that is true, then I'm going to end up with my last element down into the clamp area. I've been sick most of this week, so have not really messed with it. Hopefully Tuesday I will be feeling better and will be able to get the harness on the antenna then. Mathew Thank you, Mathew. I had been following the discussion of element spacing. Now I need to measure my spacing to see if it is in the right range - I suspect not. What was the spacing that you determined was correct for yours? Russ N4KOX --- In Repeater-Builder@yahoogroups.com, Mathew Quaife [EMAIL PROTECTED] wrote: They are 35 1/4 from top to bottom of the element. You will also need to change the phasing harness. I have one here that had the elements changed, but did not have the harness change, impedance was way out of wack. I just ordered a new harness from Cook Towers, getting ready to install it. Mathew I need to mesaure the DB224 I have for use at 145.11 Mhz. and modify as necessary. Someone had given me the 2 meter loop length but I can not locate it. Anyone know what it should be? or the range for Amateur 2 Meters vs. commercial 150+? Thanks a lot for your help. Russ N4KOX Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
I just measured mine (not as cold in North Florida as for you guys, but it was interesting to measure the deminsions on my two antennas: Both Had top element center 26 from top of pipe (so that was OK.) Both had 34.25 inch loops (top to bottom)(reasonable) Both had 62 separations from center of mount for each loop to the next (unexpected.) I was concerned that I would not have enough separation between elements - looks like I have plenty. It really surprised me that my spacing was more than the spacing for 2 meters, escpecially since the elements are much smaller than the 37 that John has and Mathew's given dimension and Cook towers confirmation of 35.25. Interesting. Russ N4KOX --- In Repeater-Builder@yahoogroups.com, kf0m [EMAIL PROTECTED] wrote: If you are looking for the length of the loops in addition to the spacing the 2 meter DB224's I just put up had 37 inch loops on a 22 ft mast. The factory element spacing was not consistent so you should definitely check your spacing per the dimensions Russ gave. I have one 150 mhz DB224 and it has 35 inch loops on an 18 ft mast. Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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: DB224 Loop Lengths for 145.110 Mhz?
If you look back at a post I did a couple of days ago The variable element to element spacing on our DB224E's new from the factory ran anywhere from 62 to 70 inches. If you do some web searches there are several methods that have been used to extend the short elements. These range from cutting the elements and making a trombone slide arrangement, to inserting a screw in the ends, to using long hose clamps and letting tails stick out the right length. We happened to be fortunate enough to have a welder in the club and he welded short stubs of aluminum tubing on the ends of each 35 inch element to extend them out to the 37 inch dimension. John Lock KF0M Wichita KS kf0m at arrl dot net -Original Message- From: highlandfl [mailto:[EMAIL PROTECTED] Sent: Sunday, January 23, 2005 5:05 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Re: DB224 Loop Lengths for 145.110 Mhz? I just measured mine (not as cold in North Florida as for you guys, but it was interesting to measure the deminsions on my two antennas: Both Had top element center 26 from top of pipe (so that was OK.) Both had 34.25 inch loops (top to bottom)(reasonable) Both had 62 separations from center of mount for each loop to the next (unexpected.) I was concerned that I would not have enough separation between elements - looks like I have plenty. It really surprised me that my spacing was more than the spacing for 2 meters, escpecially since the elements are much smaller than the 37 that John has and Mathew's given dimension and Cook towers confirmation of 35.25. Interesting. Russ N4KOX --- In Repeater-Builder@yahoogroups.com, kf0m [EMAIL PROTECTED] wrote: If you are looking for the length of the loops in addition to the spacing the 2 meter DB224's I just put up had 37 inch loops on a 22 ft mast. The factory element spacing was not consistent so you should definitely check your spacing per the dimensions Russ gave. I have one 150 mhz DB224 and it has 35 inch loops on an 18 ft mast. Yahoo! Groups Links Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * 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/
