[Repeater-Builder] Where do the temp comp resistors from ICM go?
Sorry to ask a dumb question, but I have some Maxar 50 UHF radios apart that I'm installing crystals from International, and they included what looks like 1% (light green) resistors. I can't see in the Moto manual where they would go since Moto would recommend using their parts. Just need a hey, put them here response. These are not channel elements but the small HC style units. Thanks, Tony
Re: [Repeater-Builder] Where do the temp comp resistors from ICM go?
Thanks Eric. These are actually the compensating resistors that install next to the crystal socket. I found them eventually on the schematic. Different color dotted crystals (yellow, white, green, red) require different load resistors (10 ohm, 3.09k, 7.5k and 12.4k respectively). Tony On 08/29/2010 11:18 AM, Eric Lemmon wrote: Tony, I suspect that those are temperature-compensating capacitors. Call ICM tech support and get the answer directly from the source. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tony KT9AC Sent: Sunday, August 29, 2010 8:56 AM To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: [Repeater-Builder] Where do the temp comp resistors from ICM go? Sorry to ask a dumb question, but I have some Maxar 50 UHF radios apart that I'm installing crystals from International, and they included what looks like 1% (light green) resistors. I can't see in the Moto manual where they would go since Moto would recommend using their parts. Just need a hey, put them here response. These are not channel elements but the small HC style units. Thanks, Tony
Re: [Repeater-Builder] Polyphaser Question
Remember the objective is not to take the brunt of a lightning strike, but to drain off any static that would attract that strike. Lightning is just a spark looking to close the gap, and if your antenna is closer to DC ground, it will find something closer to its potential (i.e. static charged) to hit. Any protection is better than nothing, and don't scrimp on buying the cheapest used protector. Its your equipment your protecting and potentially avoiding liability. I buy new Polyphasers for our site and sleep just fine. On 08/18/2010 08:56 AM, wd8chl wrote: On 8/17/2010 11:55 PM, Ray Brown wrote: What do you do when you want to install a small UHF linking repeater on a 4-story building that has no lightning protection on its' roof? (this is to link an ambulance at a hospital to its' base repeater 40 miles away) From what I've heard, it may not be a good idea to hook it to the HVAC, either. (sigh) Ray, KB0STN No. I would find the nearest copper pipe from either the in-house water system or the sprinkler system, and clamp to that (making sure you don't crimp the pipe!!!) using #6 or maybe #8 wire if it's REALLY close (less then 5') Again, not as good as a dedicated system, but MUCH better then nothing.
Re: [Repeater-Builder] Recording of mysterious noise
Try dropping PL on the tail. Could be a signal mixing with your repeater offset and allowing your PL to keep your repeater receiver open. For example: 442.000 transmit with 100Hz PL + 5Mhz signal = 447.000 with 100Hz PL. Doesn't matter if you use PL or DPL - it still loops back in, and ham or commercial - on UHF they both use 5Mhz split. I have a 1250Khz AM station 1 mile from my site and its 4th harmonic is 5Mhz. Probably mixing somewhere locally; less when its raining (rusty bolt theory). I run PL decode and CSQ encode to keep this from happening, or split the PL tones differently. Of course its probably not the AM stations' fault, but as Joe said its better than listening to it. Tony On 06/29/2010 06:21 AM, Joe wrote: It sounds like the squelch closes on your receiver when the signal drops, is that correct? If so, that would eliminate the possibility of the noise being the output of a repeater that has a tail timer. Can you detect any tail timer at all? If I were to make a guess, it sounds like a transmitter that is keying up with noise, such as an RF link for something, and noise on the link input is keying up the transmitter. Are you able to detect any PL tone in the noise that you hear? PL may give you a clue as to the source of the signal. Can you DF the signal? Is this in the ham band, or commercial freq? Does it happen more at certain times of the day? Is it weather related? A trick that I used was to set up a spectrum analyzer and watch 10-20Mhz at a time. I would listen to the noise and look for another signal that keys up at the same time. Very time consuming, but can be very effective. It's a crap shoot, but it beats just sitting and listening to the noise. Some ham rigs even offer a crude spectrum analyzer mode, such as my Yaesu VX7-R HT. I've used the VX7-R to look for signals with some success. (I had to read the manual to get the darn think out of the SA mode!) I used to do a lot of tracking down of interference. It helps to analyze what is not causing the noise and don't always focus on what you think it is. Eliminating what is not causing the interference many times helps you focus in on what is really causing it. Good luck and 73, Joe, K1ike On 6/29/2010 4:15 AM, gm7svk wrote: Hello, Loaded sample to files section. Has anyone encountered this sort of noise on a system or have a suggestion as to what might be generating it? Proving difficult to determine source. Thank you, Doug - GM7SVK
Re: [Repeater-Builder] Motorola radios and Zetron 37 controller
I think you mean M44GMC29C3AA's - tons for sale on eBay typically around $50 each. M = mobile 4 = 25-40W (20% duty cycle) 4 = 438-470 Mhz GMC = this series (actually German Maxtrac is where these came from) 2 = wideband deviation (5Khz, where a 0 would be 2.5Khz narrowband - not switchable, one or the other) 9 = expanded logic board - 16 channel typical, MDC1200, QCII, etc C = model revision AA = not used, just character filler Are you power cycling the radios or the Zetron? Tony On 06/22/2010 08:45 AM, Larry Horlick wrote: Is the Zetron that's locking up? I had a similar problem with a Zetron 45B. lh On Tue, Jun 22, 2010 at 5:53 AM, Joel ag...@cyberbest.com mailto:ag...@cyberbest.com wrote: We have 2 repeaters that are more or less the same. One is on 2 meters and the other is on 440. They both exhibit the same problem, they lockup after a while and then need to be power cycled. They ran for years without issue. We have the Instruction manual for the Zentron controller, but nothing on the radios. The 440 radios are Motorola M44GM29C3AA's back to back. That's the only model number on the radios. Does anyone have any information on them? A Google search shows 2 Chinese sites having them for sale on e-bay, that's it. Seems strange. Any information would be greatly appriciated, Joe Loucka -- AG4QC
Re: [Repeater-Builder] Motorola radios and Zetron 37 controller - additional
Sorry, and apologies for the extra email, just wanted the info to be complete. The 3 near the end is the range - 1=403-433, 2=not used, 3=438-470, 4=470-490, 5=490-512 Awesome radios. On 06/22/2010 09:59 AM, Tony KT9AC wrote: I think you mean M44GMC29C3AA's - tons for sale on eBay typically around $50 each. M = mobile 4 = 25-40W (20% duty cycle) 4 = 438-470 Mhz GMC = this series (actually German Maxtrac is where these came from) 2 = wideband deviation (5Khz, where a 0 would be 2.5Khz narrowband - not switchable, one or the other) 9 = expanded logic board - 16 channel typical, MDC1200, QCII, etc C = model revision AA = not used, just character filler Are you power cycling the radios or the Zetron? Tony On 06/22/2010 08:45 AM, Larry Horlick wrote: Is the Zetron that's locking up? I had a similar problem with a Zetron 45B. lh On Tue, Jun 22, 2010 at 5:53 AM, Joel ag...@cyberbest.com mailto:ag...@cyberbest.com wrote: We have 2 repeaters that are more or less the same. One is on 2 meters and the other is on 440. They both exhibit the same problem, they lockup after a while and then need to be power cycled. They ran for years without issue. We have the Instruction manual for the Zentron controller, but nothing on the radios. The 440 radios are Motorola M44GM29C3AA's back to back. That's the only model number on the radios. Does anyone have any information on them? A Google search shows 2 Chinese sites having them for sale on e-bay, that's it. Seems strange. Any information would be greatly appriciated, Joe Loucka -- AG4QC
Re: [Repeater-Builder] Re: Help Needed (Guidance and advice) tuning a DB Products Duplexer
All is not lost Josh - I'm running Motorola T1507 which are 4-can pass-only cavities on my Micor. Actually pass-only are better for commercial sites since they will help keep out a lot of intermod on either side of how they are tuned. Pass-notch on the other hand will pass the tuned frequency, but do a poor job of everything else rejection (other than the notch of course). On 05/29/2010 08:27 PM, Josh wrote: Certainly not what I was expecting... Yeah, I bought one from 'that guy'. It's more than an untrained eye - he straight lied to me... said 'under these caps are where you'll tune the capacitors' - I should have popped one off and looked down the hole. Maybe he was clued in, maybe he wasnt - either way, that's what I bought. Dangit :P So if all I have are pass cavities what 'are' they good for ? Guess I've got to find another dupelxer. j --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Jeff DePolo j...@... wrote: Ok so here's what I've got (I think) http://www.n2ckh.com/FORSALE/REPEATERS/DUPLEXERS/DB4076/DSC02678.JPG Hamvention special, 4 cavities, appears to be a DB Products 4076 family unit. My bench tools: HP 8924c w/ Spec Analyzer and Tracking Generator. There was a guy at the Hamvention that had several sets of Decibel four-cavity window filters, selling for $50 each, which, to the untrained eye, would look like an older DB4076. As you said, there would be nothing in the hole where the capacitor would be in a regular DB4076. In essecence, what you have are just plain-jane pass cavities. As a second means of confirming that you do, in fact, have a window filter, is there an antenna tee, or are the four cavities cabled together in cascade? If the latter, then you probably have a window filter. And as a third means of confirming, is there is a label on the front? If not, was there any signs of a label having once been there? If not, then that's yet one more indication that it isn't a DB4076. Decibel made two varieties of pass cavities used in window filters in that era. One had adjustable loops (less common), the other had fixed loops. If your loop connectors have a rectangular chrome plate around them with insertion loss calibration marks, you have the less-common adjustable ones. If you just see four philips-head screws and no chromed plate around the connectors, then yours is not adjustable. If you have the adjustable type, you could probably use them as a pass-only duplexer, but with mediocre isolation, even with the insertion loss cranked up higher than you'd like. If you have the non-adjustable ones, they have very tight coupling, so you're not going to get the isolation you'd need for a repeater. Did I buy a piece of junkola? Teach me obie-wan. Not junk, but maybe not what you were expecting... --- Jeff WN3A
Re: [Repeater-Builder] Micor PL encoder modification (TLN5731A)
Would this still allow the reverse-burst to pass through, or just abruptly cut off? On 05/03/2010 12:14 PM, wd8chl wrote: On 5/3/2010 1:08 PM, Jeff DePolo wrote: I'm guessing I am not the first to want to do this... I want to use a UHF Micor for a link. I want to be able to stop the PL encode immediately when a user unkeys, but I want the controller to be able to hold the transmitter up (without PL tone) for sending IDs. There appears to be no PL on/off gate on the TLN5731A encoder. The only tone gate is Q703 which only gates the out of phase tone used for reverse burst. Other than using a mechanical relay to interrupt the encoder tone output, any suggestions? Thanks, Paul N1BUG Pin 701 on the board (base of Q704) is PL Inhibit - pull to ground to kill the encoder. --- Jeff WN3A Yeah-that's it! |cP
Re: [Repeater-Builder] IDEA? Re: Micor PL encoder modification (TLN5731A)
Jeff, Good explanation, especially the fluttery/noisy user signal. Would this general theory apply for factory Micor DPL boards as well? I might run my repeater using DPL since that is what I have available and its working fine. Tony On 05/03/2010 02:36 PM, Jeff DePolo wrote: I don't have a schematic in front of me, but if your plan is to key voltage to the board on/off, this won't work ideally because the vibrasender reed takes a little time to come up to speed. Since the repeater transmitter is still keyed long after a user unkeys, just muting the encoder seems like it would work fine all by itself. Whether the radio does or does not understand reverse-burst shouldn't matter. RB would mute the receiver quicker on radios that do understand RB, but unless your courtesy tone, ID's, etc. start to be played out very quickly (like within a few hundred ms) of a user unkeying, even radios looking for RB should mute before those ID's and CT's air. Also consider what happens if a user is noisy/ratty/fluttery into the repeater. As the COR briefly goes inactive during a fade, you're going be switching PL phases. This will tend to make the user sound even more choppy on listener's radios that are using PL decode. You'd be better off not having the phase change, and just having the PL drop out briefly without RB, and then recovering in-phase when COR goes active again - less chance of having the user radio mute intermittantly. --- Jeff WN3A -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of N1BUG Sent: Monday, May 03, 2010 3:18 PM To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: [Repeater-Builder] IDEA? Re: Micor PL encoder modification (TLN5731A) My original plan was to let the transmitter PTT control the Micor encoder board as usual, but supply a valid user signal present logic input to abruptly stop the tone when there is no user signal present... thus allowing the controller to keep the transmitter keyed for IDs without PL tone. This would also kill the reverse burst capability. But wait! (this is a little complicated to explain) What if I divorced J401-2 from keyed filtered A+ on the exciter and instead used my valid user signal present logic to supply keyed filtered A+ to that pin? The controller PTT would control transmitter PTT as normal. Valid user signal logic would control the tone encoder. Suppose I then put a diode between the collector of Q707 and J401-4 (delayed keyed filtered A+) and used logic from the collector of Q707 (inverted) to pull Pin 701 low when Q707 shuts off. I think this would: 1) allow the controller to keep the transmitter keyed for *both* valid user signals and IDs by way of normal transmitter PTT 2) allow valid user signal logic to control the tone encoder in such a way that there would be no tone output unless there was a valid user signal... and allow the decoder to do reverse burst after loss of valid user signal, then abruptly kill the tone instead of reverting to normal tone. If anyone followed my poor description... are there flaws in my thinking? Perhaps I am over-engineering here? Paul No virus found in this incoming message. Checked by AVG - www.avg.com Version: 9.0.814 / Virus Database: 271.1.1/2842 - Release Date: 05/03/10 02:27:00
Re: [Repeater-Builder] Mitreks as UHF Repeaters?
Good question Paul. Remember the Mitrek RF decks are almost the same used in the MSR2000 repeater, and with their tuned helical front end make great receivers. For the transmitter however, I would not run it on its own. Also reducing the power output below 50-66% of rating might cause spurious issues. The best is to get a manual and bypass the PA, running driver power only. Then use an external amp to get your power up to where you need it. This is how every Micor, MSR, MSF repeater is designed. Motorola typically spec'd transmitters at 70.7% to get the best balance from the parts, and typically used multiple stages to get there (i.e. 200mW-2W-15W-50W). I recently picked up two 50W Mitrek Plus models that I will be using for linking duty, and will be bypassing the PA on those as well. At only 10 miles driver power only should work, but I have yet to complete that phase. Good luck on your project! You'll never know what duty cycle is needed during an event, so better to overprepare than worry. Tony On 04/26/2010 01:47 AM, Paul Plack wrote: After a few years on the sidelines, it looks as if I'm going to be jumping back into repeater ownership. I have a few nice pieces left from my last adventure, including a TX/RX duplexer and a loaded S-COM 7K, but I'm pondering choices in RF decks. This will be a local UHF machine designated as an asset for a emergency net in a suburban area, at a modest height, and the only RF device at its site. I have two Mitrek 30w UHF mobile radios, and am aware of their duty-cycle limitations, but would like to consider using them. They have channel elements, and I'm not averse to spending the money to have the elements redone properly. Looks like the pair will be 447.xx transmit / 442.xx receive. I have a couple specific questions about these radios... (1) If Mitreks are converted for full duplex, how well do they work? I'd like to have a complete, swappable RF setup, so trips to the site are short, and repairs can be done on my bench at home. (As opposed to requiring the two radios as separate receiver and transmitter.) (2) Would it be a reasonable pursuit to adapt a larger heatsink, and would that safely allow 100% duty cycle at 25-30 watts? (I'm philosophically opposed to fans which introduce the opportunity for a bearing to take the machine out of service.) (3) Any comments on the front ends? (4) I know these lack the sophistication of the Micor mobiles. Is the lack of a circulator a big deal in this application, at an isolated site with no other transmitters? (5) Was Motorola's quality in the Mitrek era still good enough to make a Mitrek preferred over, say, synthesized commercial transmitter boards from lesser manufacturers, but of more current vintage? All comments welcome. 73, Paul, AE4KR
Re: [Repeater-Builder] Repeater crystals available
I'll take the Micor elements. PM sent to Terry (hope it didn't get caught in a spam filter...) On 04/17/2010 02:58 PM, terry_wx3m wrote: I recently took 2 UHF machines off the air. I have for a Mastr II 1 5C on 442.050 and 1 EC on 447.050. These were custon built by Bomar crystal at a cost of $35 each plus shipping and are temp compensated. Send me $40 and and I will send them to you. Also for Micor, I have a KXN1052A on 443.050 TX and a KXN 1024A on 448.050 RX. These I receystalled myself with Bomar crystals. Same deal $40 and they are yours. I'd prefer paypal, but probably will wait for a money order if you ask nice. Terry wx3m.te...@gmail.com mailto:wx3m.terry%40gmail.com 301-722-0305
[Repeater-Builder] Can the 4th harmonic of 1250 AM keep UHF repeaters locked up?
Hi everyone, A while ago I was troubleshooting a bad feedback or growl problem that was impacting a UHF repeater, of which the short term workaround was to not encode TX PL (PL or DPL would keep it locked until the signal dropped enough or timed out). In doing some more research, I found a 1250kHz AM station within a mile or two that changes pattern between day and night. The interference mentioned above would appear around drive times (like 5pm) so that had me chasing other sources. Still, it was puzzling that a 5Mhz signal could be causing the feedback (it didn't appear when doing normal receiver testing with a service monitor). The recent give away was that I could hear talking underneath my test signal (like a sports show). So, if we take the 1250Khz signal or 1.25Mhz x 4 = 5Mhz. I realize that the 4th harmonic of a 5KW broadcast station isn't very powerful, but being in its nearfield might be enough to cause a mix with the UHF transmit output. Does this make sense? This phenomenon can be duplicated with both a 450 and 440 repeater system - both with standard 5Mhz offsets. I don't think any sort of filtering would work since the mix happens in the air. Only by having split PL's can the lockup be prevented, and equipment was both MSF5000 and Micor systems, through correctly tuned duplexers. Thanks, Tony
Re: [Repeater-Builder] Can the 4th harmonic of 1250 AM keep UHF repeaters locked up?
Thanks Jeff. The AM station has the same power both day and night, just goes from 2 towers to 4 to change the pattern. Rusty bolt or fence line etc seems the most likely. The problem does seem to disappear when its raining out, which helps verify this theory. It might be a needle in a haystack trying to find this, so maybe remoting the receiver might be the easiest. Thanks and I'll continue to investigate. I can try temporarily moving the frequencies apart about 100Khz and see if my 5Mhz theory holds water. Tony Jeff DePolo wrote: So, if we take the 1250Khz signal or 1.25Mhz x 4 = 5Mhz. I realize that the 4th harmonic of a 5KW broadcast station isn't very powerful Well...it *shouldn't* be very strong. It has to be attenuated 43 + 10 * log (Pwatts) as measured in the field (not at the transmitter output terminals). If you have access to a field intensity meter that covers up to 5 MHz, or a spectrum analyzer and a calibrated antenna, you can measure it yourself. AM stations that change power and/or pattern at night sometimes use a different transmitter between day and night depending on the power levels. Some stations also have pre-sunrise, post-sunset, or critical hours authorizations that are intermediate power levels between day and night power levels, or as an adjunct to daytime-only authorization. Bottom line - the 4th harmonic content may vary due to a combination of pattern, transmitter power output, or even different transmitters. but being in its nearfield might be enough to cause a mix with the UHF transmit output. Well, 1 or 2 miles isn't really near-field, but in any case, the field intensity may be relatively high depending on all of the other variables (power, pattern, etc.). Usually interference to VHF/UHF involving mixes with AM broadcast occur somewhere at or near the VHF/UHF site, not at the AM site. In some cases, the problem can actually be caused within the equipment on the ground rather than externally at the antenna or on the tower. If it's an in-the-cabinet mix, it could be caused by inadequate RF shielding. Before going on a wild good chase, I'd ensure that everything is properly RF-shielded, shielded cables are used for interconnects, grounding is good, all shields are in place, all mechanical connections (e.g. screws) are tight, no oxidizes or corroded connectors, etc. To rule out a lot of AM coming down the coax (which is fairly unlikely for most VHF/UHF antenna designs), install a high-pass filter. Even a shorted quarter-wave stub should give a fair amount of attenuation down in the MW range. If you have any in-line lightning protection (Polyphasers, et al), try removing them. But, more than likely, if in fact the AM station is the cause (either its fundamental or a harmonic), you have a passive intermodulation mix, the old rusty bolt problem. It could be in your antenna, on your tower, in your duplexer, in a corroded connector, who knows where. Divide and conquer is the only way to try to isolate it. --- Jeff WN3A Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) * To change settings via email: repeater-builder-dig...@yahoogroups.com repeater-builder-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: repeater-builder-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] zetron 48b
Check and see if the DPL is either being presented or programmed as inverted. My TP-38 panel is opposite of what I tell it to do, even though PL's always work. On 1/29/2010 3:56 PM, plaimann wrote: i have a zetron 48b controller , running 2 motorola vhf sm50 mobiles via the acdcessory connectors. im having a problem with running a dpl. when i set the controller to dpl, it will key up with no audio , but if i add audio the ctcss light drops and the repeater drops. any ideas? i run 2 pl's regularly with no problems.
[Repeater-Builder] Comm-Spec TP38 with DPL option
Hi Everyone, Picked up a nice Comm-Spec TP-38 and it appears to have the DCTCSS (DPL) board and updated firmware. I don't have any documentation on it, nor can I find anything on the Repeater Builder site. I might contact Comm-Spec for a better manual if available since the scanned versions cut off the bottom line or two, plus page two of the schematic is missing. Does anyone have information on programming this differently than the stock instructions for PL? I'm guessing its just do the 01# then enter the code, but I haven't tried it yet. Thanks for any help. If I find out any new information I'll share it back to the group and site. Tony
Re: [Repeater-Builder] Re: Comm-Spec TP38 with DPL option
Hi Skip, Actually I went to Comm-Spec's site and they have a 6-page addendum for the TP-38. Here is the link: http://www.com-spec.com/insheet/tp38tos.pdf I should have checked there first before opening my mouth on Repeater-Builder...oh well. Thanks for looking for me. Tony skipp025 wrote: Hi Tony, If you can't easily find it on line... I have it in my files and could copy and fax or mail it to you. I could scan it but I haven't had time to configure and make my replacement digital pdf scanner work yet (waiting on software from HP). So as a last resort I have it available with a bit of time and work on my end. s. Tony KT9AC kt...@... wrote: Hi Everyone, Picked up a nice Comm-Spec TP-38 and it appears to have the DCTCSS (DPL) board and updated firmware. I don't have any documentation on it, nor can I find anything on the Repeater Builder site. I might contact Comm-Spec for a better manual if available since the scanned versions cut off the bottom line or two, plus page two of the schematic is missing. Does anyone have information on programming this differently than the stock instructions for PL? I'm guessing its just do the 01# then enter the code, but I haven't tried it yet. Thanks for any help. If I find out any new information I'll share it back to the group and site. Tony Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) * To change settings via email: repeater-builder-dig...@yahoogroups.com repeater-builder-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: repeater-builder-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Rolling Pipe Sound
Scott, You are not alone in this!! I too have been fighting a problem almost exactly like this - I've tried different PL tones on RX and TX and that seemed to keep it from self-oscillating. Seems to happen more when the weather is dry and I describe it as a growl sound. Happening on a MSF5000 at a commercial site. We too have numerous broadcast towers within 2 miles, and lots of Cellular/PCS antennas around. Mine is on UHF, yours appears to be high-band VHF (from the TKR-750 K2 note). I'm still working on a resolution, but again for now try either split tone or remove PL from the transmitter (CSQ). It would keep the repeater keyed up for several seconds, then drop signal and come back again (as long as the tail remained with PL output). I've also shortened the hang timer to 3 seconds to help. It wouldn't bring up the system unless someone kerchunked it, then it started. Tony, KT9AC offtracks1 wrote: Thanks for all the post and for the web site and group. It's been very helpful to me as I have been setting up my system. My repeater system is a Kenwood TKR-750 K2, Telwave TPRD-1556 duplexer set (6 cavities), A Telwave Isolator on the PA. Running 1/2 Heilax to a Andrew DB224E antenna. This a repeater at my home as I am on a small hill. The antenna is about 40 feet vertical and 60 feet horizontally from the repeater/office. It works very well but I have had intermod issue that rears its head now and then that sounds like rolling pipe or hollow sound. I am runing a PL on both TX and RX. This sound opens up the receiver even. So my tx pl is getting back into the system. I have hunted down many noise makers in the office that could have been helping out. One was the Linksys router. I am going to replace it anyway as it makes a ton of noise I found. Changing my network from 100 to 10 on the card speed also reduced the noise levels. Still I get the rolling pipe sound now and then and it leaves as fast as it shows up. If I use my other antenna a Diamond F22 also fed with 1/2 Heliax I also get the same result. I do use a preamp but it also seems to not change with or without it. I have even ran it so the receive antenna is alone and the transmit is the other (split). I still get the rolling pipes now and then. I do have a FM radio station on 92.1 about 4 miles from me that is known to have a sloppy signal. Could it be that this is mixing with my system and creating this? Looking at getting a DCI Band pass filter on the receiver side but I am not sure if that is just throwing more money at this project and not getting anywhere still. Just wanted to see if anyone had some ideas? Scott KB7DZR Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) * To change settings via email: repeater-builder-dig...@yahoogroups.com repeater-builder-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: repeater-builder-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Rolling Pipe Sound
Scott, I also would second the reverse repeater theory. Years ago (many) we had a repeater in Western PA on 147.165 that would lock up with a Michigan repeater on 147.765 (both rightfully coordinated) and produce the pipe sound. In those days (1980s) everyone ran carrier squelch and we had some Lake Erie ducting once in a while. Its up to you, but was just a quick workaround that I started doing. Funny thing is I can get the growl when the system ran DPL and conditions are right...but its not the repeater since another temporary system I put in did the same thing. Sorry to hijack your note with my issue, but was hoping that there would be some commonality and we would both benefit. Thanks for the information on echoproducer, I might look into that. Tony offtracks1 wrote: Thanks for the quick reply The revers pair is a good point. I am in a remote area and did the full coordination but still we have had some odd ducting here as I am close to 9K mountains and I am at around 4K feet to start with. Tony I have not ran it without the tx pl. I have a few folks that like that including myself as I drop the tone before the TX, the controller is a ICS. But still for testing I may do that. I have echolink so I hook it up at night to the Ireland conference and set the system to listen only so I do not interfere with folks. Then with a program called echoproducer I can log each time the system gets kerchunched. sometimes its fine other times the log is big. Sorry I failed to put down its on 147.000 TX 147.600 RX. I have a repeater info page off of my weather station site. http://www.josephoregonweather.com/repeater.html http://www.josephoregonweather.com/repeater.html --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Tony KT9AC kt...@... wrote: Scott, You are not alone in this!! I too have been fighting a problem almost exactly like this - I've tried different PL tones on RX and TX and that seemed to keep it from self-oscillating. Seems to happen more when the weather is dry and I describe it as a growl sound. Happening on a MSF5000 at a commercial site. We too have numerous broadcast towers within 2 miles, and lots of Cellular/PCS antennas around. Mine is on UHF, yours appears to be high-band VHF (from the TKR-750 K2 note). I'm still working on a resolution, but again for now try either split tone or remove PL from the transmitter (CSQ). It would keep the repeater keyed up for several seconds, then drop signal and come back again (as long as the tail remained with PL output). I've also shortened the hang timer to 3 seconds to help. It wouldn't bring up the system unless someone kerchunked it, then it started. Tony, KT9AC Yahoo! Groups Links * To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ * Your email settings: Individual Email | Traditional * To change settings online go to: http://groups.yahoo.com/group/Repeater-Builder/join (Yahoo! ID required) * To change settings via email: repeater-builder-dig...@yahoogroups.com repeater-builder-fullfeatu...@yahoogroups.com * To unsubscribe from this group, send an email to: repeater-builder-unsubscr...@yahoogroups.com * Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Has anyone measured out-of-band rejection for a duplexer?
Hi Everyone, Without the benefit of a spectrum analyzer, I would like to find out how much rejection of out-of-band signals can be expected from a typical UHF duplexer. Have a MSF5000 on 452 that works fine with the T4084 duplexers (1500 style), but have a lot of VHF data and FM broadcast hash that is trying to make it in (the 45kW FM is about 400 yards away and the VHF data is almost 1/3 harmonic). Looking at the documentation, I can guess its about 20db per cavity (or can), but the graphs don't extend very far. So for a regular four-can duplexer I might be providing 40db of protection. I want to increase this, and plan on adding one or two more cans on the receive side, and a Sinclair preselector in-between the latter two to make up for the increased insertion loss. Just wondering if anyone ever tried/measured this, or had ideas about filtering out FM broadcast. Eric mentioned using a single 7 Sinclair cavity, but I'd like to see if I can use some spare 1500 bandpass/reject cavities first. I don't think a 1/4-wave stub will work with that much field strength prying open the MSF's front-end. Thanks, Tony
RE: [Repeater-Builder] Has anyone measured out-of-band rejection for a duplexer?
Gary, This is wonderful information! So the bottom line is for duplex operation, a pass/notch is needed to protect the rx and tx from each other, but for everything else a bandpass-only filter is the way to go. I like your idea of using the signal generator and receiver to make measurements. Also think you can generate the offending frequency and use the FM capture effect principal to know when you've reached the same signal level (to get at least a ballpark number). I often do baseline measurements (sig gen to rx), then connect up duplexers and record those final numbers. Converting the microvolts to dbm and subtracting the two give me an idea of how well my duplexers are preforming. Of course I had a local shop double check them, and I was pretty close. Some day I'll get better measurement equipment. For now simple tools and process theory are my best learning methods. I can make a crude graph to see how the overall system is working by using the sig gen and a tunable receiver (i.e. 10 or 50 Mhz steps from 50 to 500Mhz). Tony --- On Mon, 11/23/09, Gary Schafer gascha...@comcast.net wrote: From: Gary Schafer gascha...@comcast.net Subject: RE: [Repeater-Builder] Has anyone measured out-of-band rejection for a duplexer? To: Repeater-Builder@yahoogroups.com Date: Monday, November 23, 2009, 4:03 PM You can make the measurement with a signal generator and a tunable receiver that has some kind of indicator for signal strength. It doesn't even need to be calibrated. Connect the signal generator to the antenna port and the receiver to the receiver port of the duplexer. Be sure to disable the transmitter. Find a reference level with the signal generator on the operate frequency. Then tune the signal generator to the interested rejection frequency and find it with the receiver. Then note the signal generator level and increase its output to match the receive strength that you noted at the start. The difference between the two levels is the amount of rejection the filters are giving you at the frequency of interest. With a pass/reject duplexer you won't have a lot of off frequency rejection as there is not much of a pass band on that type of duplexer. There will be good pass band rejection in the space between tx and rx frequencies due to the overlap of the filter skirts but outside of either it is not much. For an added receiver filter, your pass/notch filters again will not do too much for you as far as pass band rejection goes. If you use them to reject a specific frequency, each can should give you about 30 db of notch rejection but you may have some degradation of the wanted frequency if it is far removed. And you will probably not be able to move the notch far enough such as the broadcast band. You may be able to convert the cans to pass cavities by changing the coupling loops. Then you can do the same measurement as described above to see how much rejection you will get. Also look at some pass band curves in the catalogs and you will see about how much rejection a pass cavity will give you at a given distance away from where it is tuned. 73 Gary K4FMX -Original Message- From: Repeater-Builder@ yahoogroups. com [mailto:Repeater- buil...@yahoogroups .com] On Behalf Of Tony KT9AC Sent: Monday, November 23, 2009 1:36 PM To: Repeater-Builder@ yahoogroups. com Subject: [Repeater-Builder] Has anyone measured out-of-band rejection for a duplexer? Hi Everyone, Without the benefit of a spectrum analyzer, I would like to find out how much rejection of out-of-band signals can be expected from a typical UHF duplexer. Have a MSF5000 on 452 that works fine with the T4084 duplexers (1500 style), but have a lot of VHF data and FM broadcast hash that is trying to make it in (the 45kW FM is about 400 yards away and the VHF data is almost 1/3 harmonic). Looking at the documentation, I can guess its about 20db per cavity (or can), but the graphs don't extend very far. So for a regular four-can duplexer I might be providing 40db of protection. I want to increase this, and plan on adding one or two more cans on the receive side, and a Sinclair preselector in-between the latter two to make up for the increased insertion loss. Just wondering if anyone ever tried/measured this, or had ideas about filtering out FM broadcast. Eric mentioned using a single 7 Sinclair cavity, but I'd like to see if I can use some spare 1500 bandpass/reject cavities first. I don't think a 1/4-wave stub will work with that much field strength prying open the MSF's front-end. Thanks, Tony - - -- Yahoo! Groups Links
Re: [Repeater-Builder] Help Identifying UHF Duplexer
Motorola T1504. Just tuned one last weekend and average 81dbm reject with probably 0.1uV pass loss. Good for 250W and 406-512. Lots of good documentation on the Repeater-Builder page: http://www.repeater-builder.com/motorola/t1500.html Good Luck. Bought my last set for around $140. Tony bbfmrf wrote: I have a 4 can duplexer that was removed from service. I presently have no use for this item, so I would like to sell it, unfortunately, there are no markings as to its origin. It may be a home brew, but I seem to remember Motorola selling something similar and I believe the model started with a T, but I cannot find any info. If anyone can supply me with some info on this duplexer, I would appreciate the help, and also if anyone is interested, I will accept offers. Pictures of the duplexer may be found in the Photo Section of this group in my album BBFMRF. They are the first 2 pictures labed AA UHFDuplxerFront and AA UHFDuplxerrear FYI The frequency markings on the repeater are correct and the unit should presently be tuned as marked. Replies may be posted to the group or sent directly to me at bbfmrf at yahoo.com Thanks for all your help.
Re: [Repeater-Builder] Maxtrac with no Tx PL
Accessory plug, there is an option to disable TX PL with a jumper or RSS option. f...@fitzharris.com wrote: Hi All, I have a Maxtrac with no Tx PL. I've checked the programming several times, even cloned another radio. I've tried both TPL and DPL. I've checked the Tx output on the service monitor and there just isn't any TPL/DPL there. Mic audio is there and deviating at the proper level. What else should I be looking at? Thanks, Sean
Re: [Repeater-Builder] Narrow(er) band FM
I have a GM300 narrowband mobile (M34GMC00D3A), how do I know when its programmed to do 12.5Khz? There is nothing in RSS to select, where the MTS2000 CPS allows unique modes for narrowband. Thanks, Tony Cort Buffington wrote: I said I'd report back XYL and I were out with the EX500s today. I copied the channel we normally use for simplex and changed nothing but made it a narrower channel. Results. Noise squelch seems sloppier (normally I use DPL or PL, so that really isn't to big of a deal), audio fidelity is reduced. We weren't far enough apart to really test range. I think the audio quality was still pretty good, but when do do ok, go back to channel 3 now... It's quite clear the narrow sounds quite noticeably better than the narrower. 73 DE N0MJS P.S. I also wonder about the frequency accuracy of radios going to the super-narrow band. I've looked at a lot of ham rigs on my service monitor. They are usually worse than the commercial radios in this area. Isn't that going to have a more pronounced effect? On Oct 3, 2009, at 4:22 PM, John Sehring wrote: I think it's worth repeating (no pun intended!): 0. In a narrower band FM system, with only the carrier present, you may well get a bit more ultimate quieting sensitivity (but not necessarily better SINAD) as the receiver's IF bandpass (selectivity) is narrower, letting less noise thru. However, the question is: how much of that slightly increased sensivity is actually useable? 1. Reducing FM deviation to less than about 5 kHz results in less power in the sidebands, which sidebands convey the intelligence (the carrier is just there to enable the usual demodulation (detection) process). As the detector needs the sideband energy, even granting (1) above, you'll have less recovered audio available. The signal's spectrum then begins to resemble that of an equivalently-modulated AM signal; the major difference is that with an FM signal, the carrier is 90 degrees out of phase with the sidebands, whereas with AM, carrier and sidebands are in phase. 2. Reducing FM deviation (and narrowing IF bandpass) allows more distortion in receivers at low (fringe) signal levels, so it's less able to deal with things like multipath propagation, AM noise, FM noise (yes, there is such a thing), and co-channel interference. Signal to noise ratio is thus reduced. 3. Squelch action becomes sloppier because the demodulated audio spectrum which is used for noise-operated squelch is quite a bit less when using narrower band FM. Rule of thumb for the squelch detector's bandpass: it extends from A) just above the voice audio band, say, 4 kHz, to B) about one-half the IF bandwidth. The latter is distinctly less, so the squelch sensing bandpass is less making squelch action less responsive. If you use an audio spectrum analyzer to look at a demodulated FM signal, you can see the spectral differences between 75 (FM broadcast), 25 (NTSC TV sound), 15, 5, and 2.5 kHz deviated signals, esp. as the signal strengths are reduced to zero. --John
Re: [Repeater-Builder] Re: ATSC pilot frequencies for Sig.Gen. alignment
What about a local Trunked Simulcast system for a rough reference? They should be GPS aligned somehow. Al Wolfe wrote: Pity that the guy selling all this stuff is in China. I think I'll pass. Al, k9si Re: ATSC pilot frequencies for sig. gen. alignment Posted by: wb6ymh freebsd...@hotmail.com mailto:freebsdfan%40hotmail.com wb6ymh Date: Tue Sep 8, 2009 6:56 am ((PDT)) --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, wb6ymh freebsd...@... wrote: Bob, you might consider picking up a rubidium frequency standard, they are $100 on ebay. In fact there's a $77 buy it now listing with free shipping at the moment: http://cgi.ebay.com/10MHZ-EFRATOM-LPRO-101-Rubidium-Frequency-Standard-DHL_W0QQitemZ270442620847QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3ef7a2e7af_trksid=p3286.c0.m14 http://cgi.ebay.com/10MHZ-EFRATOM-LPRO-101-Rubidium-Frequency-Standard-DHL_W0QQitemZ270442620847QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item3ef7a2e7af_trksid=p3286.c0.m14 You'll need a heatsink and a 24 volts power supply. A GPS locked standard would be ultimate, but they are more like $300. 73's Skip WB6YMH I take it back, GPS standards have come WAY down in price since the last time I looked. Here's one for $120... hmmm... tempting... http://cgi.ebay.com/Thunderbolt-PRECISION-GPS-10mhz-FREQUENCY-TIME-Standard_W0QQitemZ180399458965QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2a00a54a95_trksid=p3286.c0.m14 http://cgi.ebay.com/Thunderbolt-PRECISION-GPS-10mhz-FREQUENCY-TIME-Standard_W0QQitemZ180399458965QQcmdZViewItemQQptZLH_DefaultDomain_0?hash=item2a00a54a95_trksid=p3286.c0.m14 73's Skip WB6YMH
[Repeater-Builder] WTB: MSF5000 110W UHF Range 2 PA - TTE1754A
Good Morning, I am looking to upgrade my MSF5000 from a 40W to 110W UHF Range 2 (450-470). Would anyone have one available for sale or know where I can find one? Probably a TTE1754A from what I've been reading. Thanks, Tony, KT9AC
[Repeater-Builder] WTB: MSF5000 110W UHF Range 2 PA - TLE2512A - Corrected
Sorry, listed the wrong assembly. If anyone has one for sale or trade please let me know. Tony Tony KT9AC wrote: Good Morning, I am looking to upgrade my MSF5000 from a 40W to 110W UHF Range 2 (450-470). Would anyone have one available for sale or know where I can find one? Probably a TTE1754A from what I've been reading. Thanks, Tony, KT9AC inline: nc3=3
Re: [Repeater-Builder] Narrow Banding and VHF Low Band
Does anyone know if a MSF5000 converted to narrowband operation would be legal under Part 90 after 2013? Tony Gary wrote: Don't know where you got the below 512Mhz comment from (except perhaps a sloppy comment in a recent article printed in Urgent Communications) but here's what the R O really says; Earlier in this proceeding, the Commission took the following actions in order to bring about a timely transition to narrowband technology: (1) set January 1, 2013, as the deadline for Industrial/Business and Public Safety Radio Pool licensees in the 150-174 MHz and 421-512 MHz bands to either migrate to 12.5 kHz technology, or utilize a technology that achieves equivalent efficiency; (2) prohibited any applications for new systems using 25 kHz channels, or modification applications that expand the authorized contour of an existing 25 kHz station, effective January 1, 2011; (3) prohibited the manufacture and importation of any 150-174 MHz or 421-512 MHz band equipment capable of operating with only one voice path per 25 kHz of spectrum, i.e., equipment that includes a 25 kHz mode, beginning January 1, 2011; and (4) prohibited the certification of any equipment that includes a 25 kHz mode beginning January 1, 2011.2 Keep in mind this applies to Part 90 services and not Part 95 or 97 radio services. Gary -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of wmhpowell Sent: Monday, August 31, 2009 9:49 AM To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: [Repeater-Builder] Narrow Banding and VHF Low Band Help! The FCC rules on narrow-banding seem to be contradictory when it comes to determining if VHF low band must be converted to narrow band. On one hand, the FCC states that All below 512 MHz which implies VHF low but on the other they specifically mention VHF high and UHF, specifically NOT mentioning VHF low band. I need to come up with a specific reference from FCC docs either requiring or exempting VHF low from narrow banding requirements. Urban legend and I heard won't get the funding if VHF low must be narrow-banded - only something form the FCC can make the $$ flow. And, yes, I looked but found nothing definitive. Thanks, Bill - WB1GOT Yahoo! Groups Links
Re: [Repeater-Builder] Re: UHF Connectors for 1/2 Andrew Superflex
Is it ok to use Silver PL259's and nickel reducers (UG176)? Thanks to everyone on their input. Trying to connect a MSR2000 and T4084 duplexer set (both UHF connectors). Tony Chuck Kelsey wrote: I solder the reducer onto the heliax shield, then screw it in to the PL259 and finish the soldering - some through the PL259 holes that I have already enlarged, and the center pin last. Chuck - Original Message - From: Jeff DePolo j...@broadsci.com mailto:jd0%40broadsci.com To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Tuesday, September 01, 2009 12:14 PM Subject: RE: [Repeater-Builder] Re: UHF Connectors for 1/2 Andrew Superflex I drill a hole perpendicular to the axis of the cable through the RG59 reducer (in the smooth area above the threads) so you can get solder to flow into it, maybe that's what Chuck was referring to? For 3/8 Superflex, the OD of the cable shield is just a tad too big to screw into a PL-259 easily, so I take a drill bit and shave off the tips of the threads inside the PL-259 so the cable goes in easy, then solder on as you normally would. I never came up with a solution I liked for putting 1/2 Superflex connectors on a regular PL-259, so when I'm forced to use PL-259's I usually go with 1/4 or 3/8 'flex or buy a real Andrew connector. --- Jeff WN3A -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Chuck Kelsey Sent: Monday, August 31, 2009 5:27 PM To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: Re: [Repeater-Builder] Re: UHF Connectors for 1/2 Andrew Superflex I wasn't sure, but that rings a bell. I think I had to drill out the ones for RG58 because that's all I had on hand. You know how that goes ;-) Chuck WB2EDV - Original Message - From: larynl2 lar...@hotmail.com mailto:larynl%40hotmail.com mailto:larynl%40hotmail.com To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Monday, August 31, 2009 5:22 PM Subject: [Repeater-Builder] Re: UHF Connectors for 1/2 Andrew Superflex Chuck, if you use a reducer made for RG59 (and RG8X?) there's no need to drill. Perfect fit. Laryn K8TVZ --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com , Chuck Kelsey wb2...@... wrote: I've used 1/4 superflex with PL259 reducer. Works fine. Seems like I had to drill the reducer, but that's easy anyway. Chuck WB2EDV No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.65/2323 - Release Date: 09/01/09 06:52:00 Yahoo! Groups Links
[Repeater-Builder] UHF Connectors for 1/2 Andrew Superflex
Hello Everyone, I need to make some short jumpers UHF-male to UHF-male and have a length of 1/2 Andrew Superflex on order (actually eBay). Can I use regular silver-teflon PL259's with this cable, similar to how 1/4 superflex is used with the reducer? I can't find UHF Male connectors for 1/2 superflex at Tessco. Thanks, Tony
Re: [Repeater-Builder] Re: UHF Connectors for 1/2 Andrew Superflex
Thanks Chris. So using 3/8 superflex and silver PL259 seems tight enough? Would be better than using silver connector and nickel reducer. Just trying to build two 3' jumpers to replace old RG9. How tight can you bend the 3/8? I might also need to rebuild a duplexer replacing old/missing RG142. Tony Chris Curtis wrote: 3/8 superflex works pretty good with regular pl-259. It screws right onto the jacket. Then solder the corrugated copper through the holes of the pl-259 I've used the 1/4 w/reducer as well. I also drilled the reducer to get all the way to the copper. Chris Kb0wlf -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com [mailto:Repeater- buil...@yahoogroups.com mailto:Builder%40yahoogroups.com] On Behalf Of Chuck Kelsey Sent: Monday, August 31, 2009 1:40 PM To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: Re: [Repeater-Builder] Re: UHF Connectors for 1/2 Andrew Superflex I've used 1/4 superflex with PL259 reducer. Works fine. Seems like I had to drill the reducer, but that's easy anyway. Chuck WB2EDV - Original Message - From: kt...@ameritech.net mailto:kt9ac%40ameritech.net To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Monday, August 31, 2009 2:23 PM Subject: [Repeater-Builder] Re: UHF Connectors for 1/2 Andrew Superflex Jim, Thank you VERY much for trying this and letting me know. That will save me a lot of time with this project. I have read an article that uses 1/4 superflex with PL259 and UG176 reducers, and will order some new cables and connectors for the jumpers I need. Superflex is cheaper than RG214 and probably better shielded. Tony --- In Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com, Jim Cicirello ka2...@... wrote: Tony, I just took a piece of ½ Superflex that previously had a connector on it and tried to place a PL259 UHF MALE on it. The corrugation on the superflex is larger than the ID of the connector. The connector will go over the center dielectric but the copper corrugation on the superflex is slightly larger than the outside of the UHF Male. The only way I can see it may be possible to join the connector to the cable would be to have a sleeve extend over the superflex and the outside of the UHF connector and then solder the sleeve. This might not be as good of an idea as getting proper connectors that fit the superflex like the N Male and use an adapter to get to UHF. Good Luck JIM KA2AJH From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com] On Behalf Of Tony KT9AC Sent: Monday, August 31, 2009 12:51 PM To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: [Repeater-Builder] UHF Connectors for 1/2 Andrew Superflex Hello Everyone, I need to make some short jumpers UHF-male to UHF-male and have a length of 1/2 Andrew Superflex on order (actually eBay). Can I use regular silver-teflon PL259's with this cable, similar to how 1/4 superflex is used with the reducer? I can't find UHF Male connectors for 1/2 superflex at Tessco. Thanks, Tony Yahoo! Groups Links Yahoo! Groups Links No virus found in this incoming message. Checked by AVG - www.avg.com Version: 8.5.409 / Virus Database: 270.13.67/2326 - Release Date: 08/31/09 05:50:00
Re: [Repeater-Builder] replacing PA 30w by 100w VHF - MSR2000
Francois, I have a 100W MSR2000 UHF and all the adjustments are in the PA itself (intermittent unit). 400mW out of the exciter drives it, with no feedback. My suggestion would be to look at the schematic and rig up your own feedback circuit with a variable resistor. I'm not familiar with the 30W version, but it sounds like if the circuit is open to fail downward to zero output to protect the equipment. Tony va2rc_2000 wrote: Hello to all, we are using In Quebec City a VHF MSR2000 30 watts repeater. We are planning to install a new PA 100 watts. One question we have, on the 30w version there is cable going from the PA to the Exciter. On the PA 100w version, this cable does not exist, so the Exciter does not receive the current from the PA and we have no output. Can somebody help with this issue ? Thank you Francois VA2RC
Re: [Repeater-Builder] isolation
Other than ordering the software, is there an old-school formula that can be used for this? I been using the decibel-wheel to convert from microvolts to dbm. NORM KNAPP wrote: H How about a mastr ii pll Vhf 147.225/147.825 with db224a @ 270' with 300' ldf7-50a and 110watts. I am running 45 watts right now. Thanks De N5NPO Norm - Original Message - From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Sent: Sat Aug 22 10:22:36 2009 Subject: RE: [Repeater-Builder] isolation My CommShop calculates 99.65 dB is required. I'd definitely be looking at a six-cavity BpBr duplexer for this station. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com [mailto:Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com ] On Behalf Of kj4si Sent: Saturday, August 22, 2009 6:55 AM To: Repeater-Builder@yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com mailto:Repeater-Builder%40yahoogroups.com Subject: [Repeater-Builder] isolation Hope someone may have a program,commshop? What I need to know is what amount of isolation with duplexers that is required for a GE m2 receiver with .1...@12db and a m2 pll exciter,100 watt PA on vhf,600kc split?1/2in helix,with 4pole db224 antenna at 70 ft. thanks kj4si
[Repeater-Builder] Duplexer tuning question w/service monitor
Hi Everyone, I was helping a friend tune a Motorola T1502 duplexer yesterday, and got the following readings using a service monitor and GM300 receiver. I just want to confirm that what I did looks reasonable as I did tweak one of the band-reject loops since observing a low reading. The repeater is playing well with no desense detected. Readings below are just general noise levels keeping the squelch open. RX Pair: High-side pass 457.000 = 0.4uV High-side reject 452.000 = 500uV TX Pair: Low-side pass 452.000 = 0.4uV Low-side reject 457.000 = 30uV The 30uV initially looked bad, so I played with the coupling loop on one can only (the 1502 is a four square can design) which raised the low-side reject 457.125 to around 300uV. This put the loop near the outermost position, but I was able to keep it fairly tight while making adjustments. I know that a tracking generator is the best way to tune duplexers, but having the service monitor/receiver should be acceptable. With 85 watts into the cans, we're getting around 55 out. The cans are spec'd at 1.5dB insertion loss which seems consistent with these readings. I might try and find another set of similiar cans or Wacom 678's for this site, if nothing to have a spare set. Thanks in advance for the feedback. Tony
[Repeater-Builder] Service Monitor Question
Hi Everyone, I'm thinking about buying a used service monitor for various projects, and I've come across a few units that look good (from a price point) but I can't find any data on them. 1) Racal Dana 6113G Digital Radio Test Set Service Monitor 2) Cushman CE-4000 3) HP 8924C 4) Ramsey COM3 I realize these are NOT the preferred field service units (I like IFR myself), but for now I just want something usable here and there. Opinions on them are welcome or pros/cons. Thanks! Tony
Re: [Repeater-Builder] Mobile antenna mounting options - old reference
Funny, I was just looking at this on Friday! Makes my 1/4 trunk-mount seem less effective! http://www.larsen-antennas.com/docfiles/ASB9/Mobile/MobileSeriesDesignations.pdf Daron Wilson wrote: There was an awesome pictorial in the back of some two way manual, I'm thinking back to the Micor or Exec era. It was a study with results showing what the loss of various mobile mounting solutions were with respect to the center of the roof location used for reference. Anyone have a scan of this?
Re: [Repeater-Builder] Quantar band limits
Since you're going above frequency specs, is the Quantar anything like a MSF5000 where you need to adjust a VCO to cover the new range? Greg wrote: Hi everyone, I have a Motorola Quantar on the bench at the moment and I am having a slight issue with the programming of the unit. I have programmed plenty of these for public safety but this one is for amateur use on 70cm. The receiver, PA and exciter are all for UHF R1 (403-433Mhz) but the frequencies that need programming are: RX - 433.175 TX - 438.175 These are the base TX/RX values. When I program the codeplug in, I obviously get RX and TX errors showing up. Is there any way to trick the base into going a bit out of band to clear the errors? Normally I would just swap out the modules for the correct split and be done with it but this unit is a donation to the club and money for replacement modules isnt easy to come by. Thanks Greg
