Re: [Repeater-Builder] lowband HT antennas
Hi Al, The most simple explanation is, the higher you go in frequency, the wider the band width. This is also relevant to the diameter of the metal of the antenna structure. The fatter it is, the more the bandwidth will increase. On low band frequency's you really really have to get it Fat to increase the bandwidth. As an example a standard Mobile whip (Not a HT antenna) at 50 MHz, may yield a 1.5 to 1 VSWR over 3 MHZ. to increase it to 5 MHZ you would need to increase the diameter to about the size of about a 1/4 inch pipe. Thats why you would see better bandwidth characteristics in a 1/4 tube constructed antenna than that of the type of a mobile whip. at same frequency. So Again thats not the exact true to a formula explanation but it gets the picture in the minds eye of the electrical characteristics of an antenna, I hope its clearer not muddier :-) Richard From: hitekgearhead hitekgearh...@hotmail.com To: Repeater-Builder@yahoogroups.com Sent: Wed, June 30, 2010 10:58:06 PM Subject: [Repeater-Builder] lowband HT antennas I know I am revisiting this again but I could use some clarification. It has been stated before that the Motorola low band helical antennas have a useful bandwidth of about 1MHz. I was just wondering why that was the case, say in comparison to HT antennas in other bands. For instance, (and correct me if I am wrong) the mid UHF (430-470MHz) radios often all use the same 6 1/4 wave whip. What am I missing? I know that the first type of antenna is loaded and the other is a 1/4 wave whip, but beyond that I don't understand the fundamental differences that would allow one a wider bandwidth over the other. Please pardon my antenna theory ignorance Also, in relation to that, what use would be a 99 channel MT1000 unless one either programmed the frequencies on quite a narrow spread, or carried multiple antennas? Thanks in advance, Albert
Re: [Repeater-Builder] Re: license-free radios 1272619009.275.56317...@yahoogroups.com
Hi Geret, I have some friends in Sweden that use something like this, no one seemed to know what freq they were on. When a few of them came here to the US we were talking about this and I showed them my Motorola GM 68, ICOM U16 and GE MPI II and GE PCS radios I have on GMRS. They loved the range of these and wondered if they could use something like this back in Sweden. I looked all over the Internet for information about this and could not find a thing. But now you mention PMR, I am going to focus my research there. Where in the UE are you by the way? Many thanks for all that good info! Richard From: Geert Jan de Groot pe1...@xs4all.nl To: Repeater-Builder@yahoogroups.com Sent: Sat, May 1, 2010 7:34:56 AM Subject: [Repeater-Builder] Re: license-free radios 1272619009.275.56317...@yahoogroups.com While this one is not a huge problem, it happens too. Visitors come to Las Vegas from a lot of foreign countries. People in the UK have whats called PMR radios. It's their FRS service. The radios are all simplex, 8 channels on 6.25Khz splinter channels starting at 446.000 Yep! if you scan those channels here you DO hear activity on them! For the record, most countries in EU have license-free radios in 3 frequency ranges: - LPD (Low Power Device), 10mW, 433.075 - 434.775, 68 channels in 25 kHz raster. Not so polular beacuse 10mW doesn't get far in cities - PMR (Public Mobile Radio), 500 mW, 446.000-446. 100, 8 channels in 12.5 kHz raster: 1 446.00625 2 446.01875 3 446.03125 4 446.04375 5 446.05625 6 446.06875 7 446.08125 8 446.09375 These radios generally have PL support. Note that in EU, the 70cm band is 430.440 MHz so it is out of our bands here. These things are VERY popular - recently bought 2 radios for $35 together with charger and NiMh cells! - Digital PMR, 500 mW, 446.100-446. 200, This is like the analog PMR but uses digital voice (this is what ICOM developed D-STAR for) Note that the American FRS/GMRS radios are simply illegal here, as these frequencies were used by law enforcement till recently (so not a good choice even to chance it). You indeed might want to take this into account when setting up repeater frequencies. Hope this helps, Geert Jan PE1HZG
Re: [Repeater-Builder] Re: A warning to Land Mobile Radio Dealers
J. C. and the rest. Yes I am going to say this because it seems to have been missed. When John asked is there a frequency monitored by law enforcement And to JC who said he going to use any frequency that I have to get help (Not to bright of a statement there JC, from where do you get this grand sense of entitlement anyway?) You guys do know that in the US there is still available CB Radio Right? Chanel 9 used to be monitored prior to Cellular and there on the 40 CB channels you can Legally communicate to your hearts content. As well as on the FRS devices. And with the flood of cell phones out there now, the CB Band is very clear. Now I do have radio equipment capable of almost any freq out there, but since I am not licensed on it I would not even concede transmitting on it. Only exception where I did was when I was at a GE Radio shop from 1980 to 1995 where I would call in to the PD and Fire Dispatcher (And government bands) to confirm transmission. and all was done professionally while in maintaining of that agency's radio equipment. I find it quite strange that any Ham (if you actually are one) would think that just because you have a radio capable of transmitting anywhere would think that he was entitled to do so. And no I am not a Ham, but I do listen! I am license on GMRS, and most folks there are in some cases more professional than that of some of the childish HAM conversations I have heard (usually on simplex freqs) Now I bet this will get things stirred up now won't they? Richard From: J C jcar...@k9nzf.com To: Repeater-Builder@yahoogroups.com Sent: Sat, May 1, 2010 12:30:08 AM Subject: [Repeater-Builder] Re: A warning to Land Mobile Radio Dealers If my life is in danger, I am going to use any frequency that I have to get help. I don't care if it is a remote broadcast link frequency for a radio station! But that's me. --- In Repeater-Builder@ yahoogroups. com, La Rue Communications laruec...@. .. wrote: I forgot to add something, kind of crucial to my point at the end back there. if my life was in jeopardy then. Is there a frequency that Law Enforcement monitors for non emergency situations? For the public sector? Or would it be any officer who knows how to build their own scanners? Let me reclarify - if I was in an accident, and my radio was in reach over my cell (i.e. my cell was in my pocket, or got knocked under the seat), and I had a life threatening injury, what kind of response would that evoke? John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202 http://tinyurl. com/2dtngmn - Original Message - From: Maire-Radios To: Repeater-Builder@ yahoogroups. com Sent: Thursday, April 29, 2010 10:30 AM Subject: Re: [Repeater-Builder] Re: A warning to Land Mobile Radio Dealers you should not even think of doing that. - Original Message - From: La Rue Communications To: Repeater-Builder@ yahoogroups. com Sent: Thursday, April 29, 2010 1:10 PM Subject: Re: [Repeater-Builder] Re: A warning to Land Mobile Radio Dealers So if I had a UHF Saber, and programmed it to a Police frequency for the purposes of TX EMERGENCY info only like 911, then its required to have authorization? What if I was involved in a wreck and my radio was the only thing in reach over my cell? John Hymes La Rue Communications 10 S. Aurora Street Stockton, CA 95202 http://tinyurl. com/2dtngmn - Original Message - From: kd6aaj To: Repeater-Builder@ yahoogroups. com Sent: Thursday, April 29, 2010 9:58 AM Subject: [Repeater-Builder] Re: A warning to Land Mobile Radio Dealers Strange, considering the GMRS can come with radios you buy, before you even have the license. I guess you have to be one of the BIG boys to sell radios preprogrammed with those freqs. and there is an EXCEPTION: Title 47: Telecommunication PART 90-PRIVATE LAND MOBILE RADIO SERVICES Subpart N-Operating Requirements § 90.427 Precautions against unauthorized operation. (a) Each transmitter shall be so installed and protected that it is not accessible to or capable of operation by persons other than those duly authorized by and under the control of the licensee. Provisions of this part authorizing certain unlicensed persons to operate stations, or authorizing unattended operation of stations in certain circumstances, shall not be construed to change or diminish in any respect the responsibility of station licensees to maintain control over the stations licensed to them (including all transmitter units thereof), or for the proper functioning and operation of those stations and transmitter units in accordance with the terms of the licenses of those stations. (b) Except for frequencies used in accordance with §90.417, no person shall program into a transmitter frequencies for which the licensee using the transmitter is not
Re: [Repeater-Builder] Re: 200 watts on a repeater transmitter - was something else...
Hi guys, I think this is getting off track mostly becouse of many peoples missconception about RF Power. Seems that if you have 50 watts, and can talk 50 miles, then 200w would there for talk 200 miles right? Wrong! 200w over 50 watt is only 6db so if in tern you had a 1/4 wave on your car and can talk 50 miles with your 50 watt radio, would you then expect to talk about 200 miles if you changed it to a 5/8 antenna? Of cours not right? (Most 5/8 are typicaly 4 to 5db, so you kinda ket the idea right)? Richard From: Kevin Custer kug...@kuggie.com To: Repeater-Builder@yahoogroups.com Sent: Mon, March 8, 2010 3:03:56 PM Subject: Re: [Repeater-Builder] Re: 200 watts on a repeater transmitter - was something else... Kris Kirby wrote: I think that one would be better served by choosing an antenna appropriate to the purpose of the repeater. If you need urban coverage, choose an antenna with more null-fill, or less gain. If you have to pay for power (or make your own power!), you'll spend more time working on an antenna that will cover what you need so your transmitter can be ten watts or less. The antenna doesn't know if it's receiving or transmitting - so the antenna has absolutely nothing to do with transmit or receive balance - which is now the subject. Kevin Custer
Re: [Repeater-Builder] Re: DB-201 Measurements for 6 Meters?
By Design, Ground plane antennas are best top mounted, but of course its not always possible. That said, I have done a few and have found they tend to be fairly happy if mounting is at least 1/4 wave length away from the tower. See if you can picture this in the minds eye, 2 lengths of conduit, each threaded on one end and each with a T connector on the end, the 2 Ts tied together by a short length of conduit between them (Do this part first, about 12 should be enough) another 12 screwed in the top too attach the antenna. Screw the 2 longer pieces into this when you get on the tower. Mount the antenna and then slide it outwards. Check vswr and if needed play with what makes it the most happy by sliding it in or out. Then tighten down the clamps. I used a total of 4, 2 attached to 4 3/4 conduit clamps attached to the tower legs. It was relatively easy to slide it out to get it happy before tightening it up. I did this over 15 years ago and last time I drove past that area, I could see it was still up there. Even though that company is no longer there. But that tower with the antennas is still there. Makes you wonder if any of that is in use anymore. Good Luck! -Richard From: Chuck Kelsey wb2...@roadrunner.com To: Repeater-Builder@yahoogroups.com Sent: Sun, February 21, 2010 8:36:35 AM Subject: Re: [Repeater-Builder] Re: DB-201 Measurements for 6 Meters? First, the DB-201 was not designed for tower side-mounting, so don't expect it to work well. That said, how far away from the tower will the antenna be? There's a real good chance that the VSWR will go sour when it's side-mounted. However, I have no personal experience with that antenna, but in all the low-band installations around here, I've never seen that antenna side-mounted. Chuck WB2EDV - Original Message - From: Tim Ahrens tahr...@swtexas. net To: Repeater-Builder@ yahoogroups. com Sent: Saturday, February 20, 2010 11:59 PM Subject: [Repeater-Builder] Re: DB-201 Measurements for 6 Meters? Thanks Norm Skipp - I'll do some cutting tomorrow. Any clue what the pattern might be hung off the side of a wide spaced tower? (triangular about 15' between legs at the height the antenna will be). Thanks again! Tim W5FN
Re: [Repeater-Builder] Mastr II mods and parts
Hi Greg, There is no Mod to make the exciter do 35 watts. Its nominal value is about 200 to 300 mw, but normally 250 mw. The way to get about 35 watts is to modify the PA itself. You can bypass the final stages of the PA and just use the first stage. There are many types and some may get you close just of the driver stage. But then again like I say, there are many types to look at that have different configurations. The first question is what is the output of the PA you have? We would need to see the type and give you some guidance from that point of what is the best option. Maybe even a picture or the part number of that PA would help. Best Regards Richard. From: Greg Niles k9...@yahoo.com To: Repeater-Builder@yahoogroups.com Sent: Tue, January 5, 2010 9:33:59 PM Subject: Re: [Repeater-Builder] Mastr II mods and parts I am new to repeater building I have a GE Master II VHF repeater does GE make or is there a mod to make the exciter do 35 watts so I would not have to use a PA which I do have, just trying to make things simple. Any input would be greatly appreciated. Thanks, Greg K9GJN
Re: [Repeater-Builder] Cold MVP
Interesting note about that article. I used to do maintenance on a couple stations that were located in an elevator control room at a hospital in NW wash DC. I wounder now if they have been moved? It was a very erie place to work on a station when one of the elevators would start running. -Richard From: Eric Lemmon wb6...@verizon.net To: Repeater-Builder@yahoogroups.com Sent: Sun, January 3, 2010 8:26:41 PM Subject: RE: [Repeater-Builder] Cold MVP Randy, I am surprised that your building inspector allowed your repeater to be installed at that location. Article 620.37(A) of the National Electrical Code forbids any equipment or wiring not directly associated with the elevator to be installed in elevator control rooms or machinery spaces. In my area, a paging company installed a paging transmitter in the elevator control room at a hospital, but was ordered to remove it when the building inspector made a routine walk-through. Ironically, that paging system was installed to support the hospital's own doctor paging system! Since the hospital is the tallest building in the city, the management had another masonry room installed on the roof, with a separate entrance, specifically to contain radio equipment. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@ yahoogroups. com [mailto:Repeater-Builder@ yahoogroups. com] On Behalf Of Randy Sent: Sunday, January 03, 2010 4:38 PM To: Repeater-Builder@ yahoogroups. com Subject: [Repeater-Builder] Cold MVP Well speaking of cold we have a MVP remote RX which is a duplexed 2 meter rx to 70 cm tx that is in a elevator room on top of a 15 story building and that room is largely at near ambient temperature and now with the cold seems slow to come up. The elements were temp compensated etc and I really don't think that it is coming up off frequency. If anything it seems it there at extremely low power but not confirmed at this point. The site is in a secure site so is hard to get access to for testing. What thoughts does anyone have on this. Randy
Re: [Repeater-Builder] Repeater Kenwood TKR-720
Hello Gustavo, (in English) Try this one and tell if you can use this or not. I hope it is what you are looking for. Cheers http://www.eserviceinfo.com/index.php?what=search2searchstring=TKR-720 In Portuguese Olá Gustavo, Tente este e dizer se você pode usar este ou não. Espero que seja o que você está procurando. abraço -Richard From: Gustavo (Pu3gbw) pu3...@hotmail.com To: Repeater-Builder@yahoogroups.com Sent: Tue, October 27, 2009 1:54:17 PM Subject: [Repeater-Builder] Repeater Kenwood TKR-720 Greetings to all the group! Hello everybody I am a resident of the Brazilian city of São Lourenço do Sul, State of Rio Grande do Sul, which I am very sorry for layman the English language. I come to ask some of the friends who have possession of the old manual Repeater Kenwood TKR-720 model. Already grateful Gustavo - Pu3gbw
Re: [Repeater-Builder] Re: GE Lookout Repeater related info needed.
I also had seen this rascal on Ebay and could see by that listing it was in fact on the GOV split (160 to 172 ) and was MASTR PE portables in a box. Now being a GE tech from way back, I would not recommend this type of equipment to the the rookie's as they are very delicate to disassemble. However once together they are quite reliable. I have to ask, if you do not know what it is, why did you buy it? But I do wish you luck, Your best bet is to see if you can see what COMB numbers are on the modules, as if it is high split, you will not get it down to 2 m. Everything is quite small and I do remember that even the most experienced really did not like working on the PE's (I was lucky, I mostly did MASTR II's, and the MARC V stuff of that day.) But I did do some light field work on them while visiting Police and Forestry service while on field calls. These radios are very solid. (But not when you take them apart they are quite the beast) Good luck! -Richard From: Milt men...@pa.net To: Repeater-Builder@yahoogroups.com Sent: Sun, October 18, 2009 9:38:14 AM Subject: Re: [Repeater-Builder] Re: GE Lookout Repeater related info needed. In the second picture in the folder there is a 3 position switch to the left of the volume control. The center position is marked RPTR and another position seems to be marked MON. The remaining position marking cannot be read. What is the marking? The term Lookout Repeater is unusual; I recall seeing a Motorola radio manual marked as being a lookout repeater. The unit was, IIRC, comprised of modules from the Business Dispatcher. I believe that the functionality of the unit is unique to a specific type of operation. The use of low power modules suggests that these units were part of a larger system and possibly were used as some form of range extenders. Now the bad news; the PE series modules used in this radio are not the easiest to work on. It has been a long time since I dealt with any of the PE/PY radios but IIRC the frequency sensitive componets were not always on the circuit board. Moving one of these units from 166 to 146 will involve a large amount of work. As always if one wishes to start on such an adventure, manuals are a must along with a knowledge of if and how the unit functions on the existing frequencies. Milt N3LTQ - Original Message - From: lsasmazel lsasma...@comcast. net To: Repeater-Builder@ yahoogroups. com Sent: Saturday, October 17, 2009 8:19 PM Subject: [Repeater-Builder] Re: GE Lookout Repeater related info needed. This unit come from Alaska regarding to seller it sat in the boxes and wait to get deployed. But it never happened. Frequencies are ; TX : 166.850 Mhz, , 166.850 Mhz RX: 164.425 Mhz, 164.425 Mhz I just figured out that this is one frequency unit :) Levent - WW2L --- In Repeater-Builder@ yahoogroups. com, Eric Lemmon wb6...@... wrote: Levent, The pictures do lend credence to the special part theory. Please advise what the two receive and two transmit frequencies are. Do you have any idea what company or agency owned this device? It's a long shot, but it is always (well, sometimes) possible to track down the previous owner, locate the radio shop that maintained it, and possibly identify the documents you need- if they won't just hand them over. Knowing the frequencies used is a giant first step in that process. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@ yahoogroups. com [mailto:Repeater-Builder@ yahoogroups. com] On Behalf Of lsasmazel Sent: Saturday, October 17, 2009 4:49 PM To: Repeater-Builder@ yahoogroups. com Subject: [Repeater-Builder] Re: GE Lookout Repeater related info needed. Sorry I forget the mention I put the picture under GE Lookup Repeater folder. There ais one more Number I find it is on the back of the unit and it is PL19D424600G4 this is on the back of the box. 73 Levent - WW2L --- In Repeater-Builder@ yahoogroups. com mailto:Repeater- Builder%40yahoog roups.com , Eric Lemmon wb6fly@ wrote: Levent, The component number 19C320943G1 is a SPCL COMP BD. I think it's time to take some pictures of this device, since it seems to be an oddball unit that was not a regular production item. Is there no label or tag on the outside of the box, which might give this thing a name or a model number? Without a clear identification of the whole unit, all we can determine is that it is a special part that incorporates some PE handheld modules. Regarding power requirements, a typical 5-watt radio draws about 2 amperes during transmit. Add 1 amp or so for running the controller, and you can assume that a 5-amp supply will suffice. But, be careful to determine what voltage is required to run this thing, before hooking up your favorite Astron power supply. The unit may require 7.5 or 10 VDC, and you don't know that without more
Re: [Repeater-Builder] Need help
Hi Walt, Measure the radials of the ground plane, that might get you close. If there near about 6 inches then its UHF, if they are near around 15 to 18 then it would be in the VHF rage. But a picture could help some one spot it right away. Regards -Richard From: sjotrollet sjotrol...@yahoo.com To: Repeater-Builder@yahoogroups.com Sent: Thu, October 15, 2009 3:46:27 PM Subject: [Repeater-Builder] Need help Am assisting in an estate (I'm an oldie that works CW on 160m so this is stuff is strange to me). Anyway, there is an antenna in the mess that we cannot identify. The SK was DEEP into VHF UHF (ran 2 repeaters just for him and XYL) so feel it is in that range. Heres the poop: (at least all we know): Total length: 11'6 LOA, of which 9' 6 is about 1/2-5/8OD fiberglass and 2' is a metal sleeve (where I would think a clamp to a mast would go. Its fed at the bottom by coax Only ID info on it is that is made by Antenna Specialists Co (can't find anything online on them) There is a possibility that in the lower area there might be a metal collar with 3 horizontal radials (ground plane)(such a gadget has turned up but we don't know where it belongs). Any help you guys can render will be greatly appreciated (especially any URL links to a picture catalog, freq's it covers, power rating, etc 73 Walt (N4GL)
Re: [Repeater-Builder] GE Mastr II parts
Hi Bob, You won't know until you ask the seller for the part number. But for the price I would not fuss over trivial matters such as what split it is. The rest of it is worth that just for the spare parts. -Richard From: n...@no6b.com n...@no6b.com To: Repeater-Builder@yahoogroups.com Sent: Monday, September 14, 2009 9:30:18 PM Subject: Re: [Repeater-Builder] GE Mastr II parts At 9/14/2009 10:57, you wrote: Hi Gilles?xml: namespace prefix = o ns = urn:schemas- microsoft- com:office: office / The easiest place is eBay, here is one for sale right now. http://cgi.ebay. com/GE-MASTR- II-UHF-Receiver_ W0QQitemZ2303762 91330QQcmdZViewI temQQptZLH_ DefaultDomain_ 0?hash=item35a37 f3c02_trksid= p3286.c0. m14http://cgi.ebay. com/GE-MASTR- II-UHF-Receiver_ W0QQitemZ2303762 91330QQcmdZViewI temQQptZLH_ DefaultDomain_ 0?hash=item35a37 f3c02_trksid= p3286.c0. m14 How do we know it's an 88-split UHF (450-470 MHz)? It could be 470-494 or 494-512 MHz. Bob NO6B
Re: [Repeater-Builder] GE Mastr II parts
Hi Gilles The easiest place is eBay, here is one for sale right now. http://cgi.ebay.com/GE-MASTR-II-UHF-Receiver_W0QQitemZ230376291330QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item35a37f3c02_trksid=p3286.c0.m14 I was personally looking at this for spare parts but of course I yield to the needy first..;-) Best regards Richard From: adjiqc adj...@yahoo.ca To: Repeater-Builder@yahoogroups.com Sent: Monday, September 14, 2009 10:31:20 AM Subject: [Repeater-Builder] GE Mastr II parts Hi All, I am new to this group and I was wondering if someone could help us out, we are an amateur radio club and our UHF repeater died so we are looking for parts. If someone would know where to get the following it would be appreciated. 1- High split 450-470MHZ receiver for the repeater 2- Tone board 3- Or if someone would have a full repeater in the UHF high split Regards Gilles VE2GFV
Re: [Repeater-Builder] GE Mastr II parts
I very my search quarry just to get different results. Never know how folks are spelling things. I have even had good luck finding stuff by incorporating CB in my search. Got some pretty good deals that way. -Richard From: de W5DK w...@gvtc.com To: Repeater-Builder@yahoogroups.com Sent: Monday, September 14, 2009 2:29:42 PM Subject: RE: [Repeater-Builder] GE Mastr II parts Dang, I just found out my saved searches were missing something!! That auction has an unusual local oscillator with those coils? I don’t remember ever seeing one before. Heard of them, just ain’t seen one. Don W5DK From:Repeater-Builder@ yahoogroups. com [mailto:Repeater- buil...@yahoogro ups.com] On Behalf Of Richard Fletcher Sent: Monday, September 14, 2009 12:57 PM To: Repeater-Builder@ yahoogroups. com Subject: Re: [Repeater-Builder] GE Mastr II parts Hi Gilles The easiest place is eBay, here is one for sale right now. http://cgi.ebay. com/GE-MASTR- II-UHF-Receiver_ W0QQitemZ2303762 91330QQcmdZViewI temQQptZLH_ DefaultDomain_ 0?hash=item35a37 f3c02_trksid=p3286. c0.m14 I was personally looking at this for spare parts but of course I yield to the needy first..;-) Best regards Richard From:adjiqc adj...@yahoo. ca To: Repeater-Builder@ yahoogroups. com Sent: Monday, September 14, 2009 10:31:20 AM Subject: [Repeater-Builder] GE Mastr II parts Hi All, I am new to this group and I was wondering if someone could help us out, we are an amateur radio club and our UHF repeater died so we are looking for parts. If someone would know where to get the following it would be appreciated. 1- High split 450-470MHZ receiver for the repeater 2- Tone board 3- Or if someone would have a full repeater in the UHF high split Regards Gilles VE2GFV
Re: [Repeater-Builder] Antenna SWR = Desense?
Hi Tim, My first suspect would be the cable from the duplex er feeding the 7/8. I have problems there more than anything. Although the 2.1 swr is a bit high I would shoot the easy target first. BR _richard From: tahrens301 tahr...@swtexas.net To: Repeater-Builder@yahoogroups.com Sent: Tuesday, September 1, 2009 3:03:29 PM Subject: [Repeater-Builder] Antenna SWR = Desense? Hi folks, Just a bit of an update... got the 6 cavity Telewave duplexer tweaked up - looks like it pretty much hit the specs in the data sheet. With a dummy load at the 'antenna' port, I used an iso-tee to inject a signal at both the receiver input, and between the antenna port the dummy load. With a weak signal, both places showed me that there was no desense. Very weak signal would hold in the repeater. However, putting the system on the antenna (a 150-160 mhz DB-224 100' horizontally 10' vertically separated) through a metal building fed with 7/8 heliax, there seems to be no end to the desense! The wattmeter shows 30 watts forward 3 watts reflected at the antenna port, if my math serves, it's less than 2:1. Can the less than 1:1 match be the culprit? Thanks, Tim W5FN
Re: [Repeater-Builder] Re: Antenna SWR = Desense?
Tim, This might be it. I miss read the previous. Try the Ringo for grins and see what transpires. Might be a bad connection on the old antenna. BR -Richard From: tahrens301 tahr...@swtexas.net To: Repeater-Builder@yahoogroups.com Sent: Tuesday, September 1, 2009 4:02:35 PM Subject: [Repeater-Builder] Re: Antenna SWR = Desense? Hi Joe, The repeater/duplexer is in my workshop (a large metal building). The heliax goes out the window to a smaller portable building about 100' away (horizontally spaced). The antenna is on that building about 10' off the ground. Don - took the dummyload analyzer to the end of the hard line, fed it into the iso-tee there. No desense is noted. Something's not right when the antenna gets hooked up. Maybe I should put up the ringo for a test. at least it's probably a bit better of a match. --- In Repeater-Builder@ yahoogroups. com, Joe k1ike_mail@ ... wrote: You state DB-224 100' horizontally 10' vertically separated. I don't understand what you mean by that. Joe tahrens301 wrote: However, putting the system on the antenna (a 150-160 mhz DB-224 100' horizontally 10' vertically separated) through a metal building fed with 7/8 heliax, there seems to be no end to the desense!
Re: [Repeater-Builder] Re: DB-4050WB Duplexer
Hi Tim, Is usually a good idea to test the Duplexer while on a dummy load. I usually like to use my Marconi 2955 Duplex mode to tune the duplexer. Once I am happy with that then I go to the antenna see how that looks. I like to use the lowest value element I can find for my bird meter to tackle the reflected power. And I like to use an HT programmed in 1 mhz steps (11 channels, so I can compare 5 mhz up and down) That gives me a reference in what direction I need to focus tuning. If you are on 440, be sure to keep reference to the transmit freq first. Then give it a sanity check on the input freq. Be safe when you head to the hill and be sure you don't go alone. Never know what you can get into in those remote locations right. Good Luck Richard From: tahrens301 tahr...@swtexas.net To: Repeater-Builder@yahoogroups.com Sent: Tuesday, August 25, 2009 3:22:52 PM Subject: [Repeater-Builder] Re: DB-4050WB Duplexer Hi Richard, Thanks for the info. This is a new installation, and I do have some reflected power. That will be taken care of very soon. Fortunately, all the repeater components are still here at the house. Running the 'real' heliax to the DB-224 on a pole, so it's pretty close to what it'll be like on the hill. Thanks again, Tim W5FN --- In Repeater-Builder@ yahoogroups. com, Richard Fletcher rickflet03@ ... wrote: Hi Tim, The most common cause for desense is connections and not actually the duplexer. Especially if there was no desense prior. First I would check the link from the duplexer to the hard-line (If this fits into your site configuration) put a meter right there where the hard-line comes into the building. If you get any reflected power, then your desense problem is most likely at the antenna or from the meter and up the cable. If you think there is a power reduction there, well that jumper to the hard-line is bad. If that looks good, then check all the connections on the station (before you start turning the screws). Believe me, I have had to re-tune many a duplexer that someone turned the screws on because of desense that was a cabling issue and not the duplexer. God luck on the adventure.. BR -Richard _ _ __ From: tahrens301 tahr...@... To: Repeater-Builder@ yahoogroups. com Sent: Tuesday, August 25, 2009 12:43:30 PM Subject: [Repeater-Builder] DB-4050WB Duplexer Hi Folks, I was checking e-bay for duplexers last night, and came across a DB-4050 that the user said was a pass/reject duplexer. It looks almost identical to one that has been giving me some desense issues, but had a marking of SP-1894. The cabling looks a bit different, but functionally equivalent. Has anybody used one of these, and is it really a pass/reject, or just a group of notch cavities? I've seen the specs on the data page here, but it only gives the specs doesn't call it anything specifically. I don't plan on bidding on it, as I have a 6 cavity BpBr Wacom coming from a friend, but after all of the pain I've had with the DB prod box, was just curious. Thanks! Tim W5FN
Re: [Repeater-Builder] GE key needed
Hi All, Any one looking for a Mastr II key (Mobile or base/repeater) only needs to go to the local lock smith (Not Home Depot or Lowes, they only copy) The Smith can cut you a key from the book. It is a BF10a. (I have done it) Best Regards Richard Fletcher From: Mike Morris WA6ILQ wa6...@gmail.com To: Repeater-Builder@yahoogroups.com Sent: Tuesday, August 25, 2009 3:37:29 AM Subject: Re: [Repeater-Builder] GE key needed At 05:40 PM 08/24/09, you wrote: Anyone want to sell an extra Mastr II Key? wx3m.te...@gmail. com Which one? Mobile or base/repeater cabinet? This might help clarify things: http://www.repeater -builder. com/keyspage/ keyspage- index.html
Re: [Repeater-Builder] DB-4050WB Duplexer
Hi Tim, The most common cause for desense is connections and not actually the duplexer. Especially if there was no desense prior. First I would check the link from the duplexer to the hard-line (If this fits into your site configuration) put a meter right there where the hard-line comes into the building. If you get any reflected power, then your desense problem is most likely at the antenna or from the meter and up the cable. If you think there is a power reduction there, well that jumper to the hard-line is bad. If that looks good, then check all the connections on the station (before you start turning the screws). Believe me, I have had to re-tune many a duplexer that someone turned the screws on because of desense that was a cabling issue and not the duplexer. God luck on the adventure.. BR -Richard From: tahrens301 tahr...@swtexas.net To: Repeater-Builder@yahoogroups.com Sent: Tuesday, August 25, 2009 12:43:30 PM Subject: [Repeater-Builder] DB-4050WB Duplexer Hi Folks, I was checking e-bay for duplexers last night, and came across a DB-4050 that the user said was a pass/reject duplexer. It looks almost identical to one that has been giving me some desense issues, but had a marking of SP-1894. The cabling looks a bit different, but functionally equivalent. Has anybody used one of these, and is it really a pass/reject, or just a group of notch cavities? I've seen the specs on the data page here, but it only gives the specs doesn't call it anything specifically. I don't plan on bidding on it, as I have a 6 cavity BpBr Wacom coming from a friend, but after all of the pain I've had with the DB prod box, was just curious. Thanks! Tim W5FN
Re: [Repeater-Builder] Re: The True Pattern of a DB224
Laryn You did not mention what antenna you are talking about, however most are typically in the 6 to 8 DB range for a four bay. But for exact information you would be best to go to the manufacturers web site and read the specs from there. There are also many documented antennas on Repeater builder dot com where you can find lots of info on them. Remember that Google and Bing are your friend! just type in the make and model of your antenna and you will find more than enough on your antenna. Best Regards Richard From: Laryn Lohman lar...@hotmail.com To: Repeater-Builder@yahoogroups.com Sent: Thursday, July 23, 2009 10:35:34 PM Subject: [Repeater-Builder] Re: The True Pattern of a DB224 So the original question still stands. What is the actual gain of an antenna with all four dipoles in line, and perpendicular to them in both directions? Laryn K8TVZ
Re: [Repeater-Builder] Help with a CSI TP 154 Tone Panel
Hi Dick, I have a bunch of these on the air and noted same problem when I used my ICOM U 16 a while back. Check that the *123456* turns on the display. Then do the *123456# and watch closely that each key press shows up on the display. You might have one tone that is not decoded correctly. Try another device and see what happens. I Used a GE PCS and a Motorola GP 68 and they worked fine. I later tried re-tuning the repeater IF stage later on since I knew that radio worked before, and Whala, I had access again on my U16. So seems it might be a sensitivity to the tones that is going on there. I have 5 of my Mastr II stations on the TP-154's, 1 is on the TP-163. My other 2 stations that don't have the PLL exciters are using the CSI Supper 32 and the old TP-38. All of these things have been stable for many years. My First TP-154 I purchased in 1993. Its been on the air ever since. Good luck, BTW I have a Motorola Motrac Repeater I would love to wire up for the TP-154 if I could just get the manual on it. I have had it on the air on GMRS on its single PL of 103.5 for nearly TEN years. Anyone wired one of these up, I am a GE guy and not had much dealing with the Motrac other than when its 10 ton PA gave out. (Its seems to run fine on just the exciter) Regards Richard From: rabre...@sbcglobal.net rabre...@sbcglobal.net To: Repeater-Builder@yahoogroups.com Sent: Saturday, June 27, 2009 9:38:48 PM Subject: [Repeater-Builder] Help with a CSI TP 154 Tone Panel Hi Gang I need some help with a CSI Tone Panel #154. Most of the programming works from the touch tone telephone jack in the back. What I can not get to work is programming over the air. I am using the factory pass word *123456# , I can see the digits on the display when I punch them in from a talkie. It never goes into program mode. It will however put the unit into PL display by pushing *123456* Any answers for my problem Thanks 73 Dick
Re: [Repeater-Builder] Where to install my repeater antennas
I know you all will laugh at this one, but they say necessity is the mother of invention. A while back a friend had the chance to try a tower site and wanted a simple and quick way we could check coverage. So with 2, ¼ wave NMO whole mount antennas and 2 18” satellite dish pans. I mounted both antennas. Since these mounts were not shielded inside I used a couple strips of foil tape to insure the shielding. Then panned them face to face with one then being on the top and other one inverted on the bottom. Then we dropped 2, 50’ feeds of 9913 to a Custom MVP Repeater on a car battery at the base of the tower. The Dish was set in the tower structure and laid down inside pretty nicely. We then had a couple different folks access it from various areas and we drove around checking coverage on a GMRS freq. The surprising thing was that with the RX as the top and the TX was inverted. There was enough isolation that there was no desense on the 15 watt TX and the receiver was running a nice .2 uv, 12db sinad. The location worked so well that he made arrangements on an adjoining tower at the same site. He had his GMRS there for the full term of the license and removed it when everyone started using cellular’s instead. (This was back in the MID 90’s). Oh and when he went permanent he did use a real antenna and Duplexer. But it was the same Custom MVP radio. Just thought I would share that since we were discussing dual antennas and no Duplexer options. Regards -Richard From: Barry ate...@hotmail.com To: repeater-builder@yahoogroups.com Sent: Saturday, June 27, 2009 8:46:58 PM Subject: RE: [Repeater-Builder] Where to install my repeater antennas You are going to need a lot more isolation than you are contemplating , either fit cans on a common stick or separate by a couple of hundred feet _ _ __ To: Repeater-Builder@ yahoogroups. com From: agrimm0...@yahoo. com Date: Sat, 27 Jun 2009 21:01:58 + Subject: [Repeater-Builder] Where to install my repeater antennas This isn't the most difficult question to answer, and I figure it can be answered relatively easily. I currently over the past few weeks constructed a GMRS repeater for my neighbor hood to use. It is constructed of 2 maxtrac radios one set at just 30 watts tx. I plan to use 2 antenna's so no duplexer is needed with some good Heliax cable running at least to the TX antenna. I have 40 ft of tower that I plan to mount the antennas on. One antenna is a Celwave (RFS) 6db gain antenna. And the other is just a plain 1/4 wave NMO style mount antenna. Which is the best way to install these antennas on my repeater? Celwave on the transmit end and at the top, or 1/4 wave on the Transmit and celwave on the receive? Also which antenna should be mounted on top of the tower? _ _ _ _ _ _ Looking for a new car this winter? Let us help with car news, reviews and more http://a.ninemsn. com.au/b. aspx?URL= http%3A%2F% 2Fsecure% 2Dau%2Eimrworldw ide%2Ecom% 2Fcgi%2Dbin% 2Fa%2Fci% 5F450304% 2Fet%5F2% 2Fcg%5F801459% 2Fpi%5F1004813% 2Fai%5F859641 _t=762955845 _r=tig_OCT07 _m=EXT
