RE: [Repeater-Builder] Re: Astron Power Supply Crowbars
> Let's not lose sight of the fact that the motor circuits that are > generating the spikes should be examined for ways to reduce or eliminate > same. Moreover, tinkering with the power supply crowbar circuits is > really treating the symptom rather than the problem. I have to disagree. Both of my rack mount 50 amp supplies have done this, on remote sites or in the garage with NO problem on the input side. If you try to draw more than 10-12 amps when you turn them on, it immediately crowbars. The only way to get it to run is to turn it off, drain the caps, remove the load and turn it back on. Then you can attach the load *spark* and it works fine. That is the design flaw that I feel needs to be corrected. 73 N7HQR Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Astron Power Supply Crowbars
I have never had an RS (linear) Astron power supply go into crowbar mode, but I can see why a healthy spike could cause that to happen. I have RS-7, RS-12, RS-20, and RS-35 units that have been working fine for many years, although all of my new units are SS (switching) supplies. The RS-35M has a typical crowbar circuit, which comprises an SCR across the output, and a simple trigger circuit. The gate of the SCR has a 0.1 uF capacitor, C102, to bypass spikes and prevent (?) false operation. My gut feeling is that this capacitor should be much larger to do its job reliably; I would replace it with a 2.2 uF tantalum capacitor in parallel with a 510 pF silver-mica capacitor. Let's not lose sight of the fact that the motor circuits that are generating the spikes should be examined for ways to reduce or eliminate same. Moreover, tinkering with the power supply crowbar circuits is really treating the symptom rather than the problem. 73, Eric Lemmon WB6FLY Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: Astron Power Supply Crobars
Rebuilding the original RS-35 regulator board doesn't fix the design problems. I have a box full of old astron regulator boards that I should sell on Ebay, but I'm afraid someone will place them in service and damage their equipment. skipp [EMAIL PROTECTED] www.radiowrench.com/sonic > "Mark Holman" <[EMAIL PROTECTED]> wrote: > Is that board rebuildable ?? > > MH > - Original Message - > From: "Joe D" <[EMAIL PROTECTED]> > To: > Sent: Wednesday, September 01, 2004 8:39 AM > Subject: [Repeater-Builder] Re: Astron Power Supply Crobars > > > > Allow me to elaborate. > > > > I have an RM-35M. It has been in continuous repeater service for > > more than 10 years without a hiccup. > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: SEA 222 ACSB Repeater P.A. re-use?
re: 220 trunking system pa's. sold supplied with SEA Equipment. There are 3 different 220 trunking system pa's around, one is the factory SEA unit, two are made by Milcom/Cresend Tech and one of those is branded as a Uniden. I have one of the Milcom and 5 of the Unidens, the Milcom Unit pretty much works ok on 224 FM as-is. The uniden version is very frequency selective and won't work above 222 without mods. I've not had my hands on the SEA branded unit, but I'm told it's a pain to work with. good luck skipp www.radiowrench.com > "John Everson" <[EMAIL PROTECTED]> wrote: > Hello to the group. > > I know that the SEA ACSB repeater itself is useless. I was wondering > if anyone has taken the time to fool around with the PA assembly to > see if it has any use for a 222-225 FM amp? I fell into two of these > things. I have seen some that were used just for the enclosure and > nothing else. > > Perhaps that is all they are good for. > > Thanks. John Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: KENWOOD TKR-850 UHF REPEATER "YES", it can be tuned in the Ham Band
re: Kenwood Repeaters in the Amateur (Ham) Band. Hello there, Kenwood might not ship the tkr-850 tuned into the ham band, but any Authorized Dealer doing more than blowing radios out the door should be able to supply the repeater tuned to/for your frequencies. There might sometimes be a small charge for special tasks, but a Dealer who claims to provide real service should be able to provide shop service or supply you the manuals if you care to do it yourself. I can do both... If you can't find the manual easily enough, I can and am always willing to order one for you... should I not already have it in stock. There are guys on Ebay selling printed manuals below my dealer cost (go figure), if you're counting pennies, you might check them out with normal cautions in place. cheers skipp skipp025 at yahoo.com www.radiowrench.com > To answer your question and speculation about whether > or not the Kenwood TKR-850 will tune and operate in > the amateur band, well the answer is "YES". Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: [Repeaters] 2 UHF receivers, one antenna
Kevin: I'd like to add to the other fine responses that have suggested the potential ill effects of tying two receiver inputs together without isolation. To determine if this is actually the problem, try replacing the second RX with a dummy load at the receiver end of the cable. If you still have the same loss in range, then it's probably safe to consider some kind of splitter that doesn't offer a lot of isolation, such as the odd-quarter wave "Q" sections to match the sum of the two loads to the line at the T connector. Otherwise, you're likely to need a bit more isolation that you could get from a resistive splitter. Keep in mind though, that resistive splitters seriously affect your systems noise figure and are only a good idea after a preamp. In any case, the proper impedence match as opposed to just the T may make a difference. If you do use a preamp before the splitter, keep the gain of the preamp down to avoid overload problems--particularly at a high profile site. Chuck - N8DNX On Mon, 6 Sep 2004, Kevin Berlen wrote: > Over the weekend, I added a second UHF control receiver at one of the sites > I take care of. The control RX antenna is up about 150ft. Previous to > adding the new RX, I could easily access the first RX about 25 miles out. > Since adding the second RX, I can only access either one about 12-15 miles > out. I simply put a "tee" connector on the polyphaser and connected both > lines to it. Not the best engineering practice, but I have gotten away with > it before. Does anyone have an idea about how to properly match two > receivers to one antenna? The receivers are located in different racks in > different parts of the building. I know Motorola and GE had passive devices > to do this job. Is there a way to build something "homebrew" to do this > job? TIA, and 73, > > Kevin, K9HX k Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: 2 UHF receivers, one antenna
--- In Repeater-Builder@yahoogroups.com, Kevin Custer <[EMAIL PROTECTED]> wrote: > Kevin Berlen wrote: > > >Over the weekend, I added a second UHF control receiver at one of the sites > >I take care of. The control RX antenna is up about 150ft. Previous to > >adding the new RX, I could easily access the first RX about 25 miles out. > >Since adding the second RX, I can only access either one about 12- 15 miles > >out. I simply put a "tee" connector on the polyphaser and connected both > >lines to it. Not the best engineering practice, but I have gotten away with > >it before. Does anyone have an idea about how to properly match two > >receivers to one antenna? The receivers are located in different racks in > >different parts of the building. I know Motorola and GE had passive devices > >to do this job. Is there a way to build something "homebrew" to do this > >job? TIA, and 73, > > > > If you are working with just receivers, and are lucky enough not to have > a bunch of RF coming down the coax, I have had good success in using a > simple CATV splitter. > > Kevin And along with that I'd inject signals using an iso-tee in the antenna coax (or stable weak signals over the air) on each receive frequency and touch up each front end. You might be surprised... Laryn K8TVZ Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: 2 UHF receivers, one antenna
You should try to keep impedances matched and have a little isolation too. A Wilkinson splitter is simple and effective. Get yourself some 75 ohm coax, cut it to a quarter wave with velocity factor considered. Also get a 100 ohm carbon comp resistor and some coax jacks of your choice. I like bnc's. A pretty good background on Wilkinsons is here... http://www.microwaves101.com/encyclopedia/Wilkinson_splitters.cfm If you pay attention to the dimentions you will have pretty close to perfection at much less than the cost of a mini circuits. But go with mini circuits if you have the budget. td wb6mie Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: 2 UHF receivers, one antenna
You could build a Wilkinson 2 port splitter. Click here. http://bellsouthpwp.net/h/w/hwingate/wilkinson.gif Henry Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] KENWOOD TKR-850 UHF REPEATER "YES", it can be tuned in the Ham Band
To answer your question and speculation about whether or not the Kenwood TKR-850 will tune and operate in the amateur band, well the answer is "YES". I have just finished tuning and installing my Kenwood TKR850 repeater two weeks ago at one of our repeater sites in south eastern Idaho. My frequencies were on 441 Mhz Receive and 446 Mhz Transmit. I had to tune the Receiver Helical front end and set the VCO's. It made factory spec's after tuning. Mine was a 450-470 mhz version. The programming and tuning took less than one hour. I know of another local ham who tuned his TKR-850 in the Amateur bands. His receives at 443 and transmits at 448 Mhz. That's two TKR-850 repeaters that I know of that have been tuned successfully to the 440-450 band from the 450-470 band. I received my manuals in PDF format. I will check to see if I can send you a copy. Thanks, John Lloyd, K7JL Intermountain Intertie http://www.ussc.com/~uvhfs/snowlink.html Date: Sat, 04 Sep 2004 09:45:34 -0700 From: Eric Lemmon <[EMAIL PROTECTED]> Subject: Re: KENWOOD TKR-850 UHF REPEATER Can it be tuned and Programed in the Ham Band The answer is "probably." The fact that others have tuned a TKR-850 to the 70cm band is not an absolute guarantee that your unit will do the same. It may work fine, or it may barely make it. The TKR-750 and -850 repeaters have manually-tuned bandpass filters in the front end that must be optimized for the Ham bands. As delivered, the filters in the TKR-850 are optimized for 450-470 MHz, but still need to be tweaked for maximum receive sensitivity. Also, the RX and TX VCOs need to be adjusted slightly to ensure that they operate over the optimum locking range. Like most RF equipment, operating a TKR repeater outside of its specified band carries some risk; it's best to minimize the risk with careful tuning. Before you attempt to tune this repeater, get a Service Manual from Pacific Coast Parts, about $23. Leave the repeater power on while you're waiting for the manual, so that the reference crystal oscillator can "settle in" to a stable frequency. Every TKR repeater I have set up needed to have the reference oscillator tweaked slightly to bring it exactly on frequency. 73, Eric Lemmon WB6FLY aj4ef wrote: > > KENWOOD TKR-850 UHF REPEATER Can it be tuned and Programed in the > Ham Band? > The 450-470 Mhz Model. > I need it to TX 442.100 RX 447.100 > Thanks for the help. > ___ Do you Yahoo!? Win 1 of 4,000 free domain names from Yahoo! Enter now. http://promotions.yahoo.com/goldrush Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] 2 UHF receivers, one antenna
--- Kevin Berlen <[EMAIL PROTECTED]> wrote: > Over the weekend, I added a second UHF control > receiver at one of the sites > I take care of. The control RX antenna is up about > 150ft. Previous to > adding the new RX, I could easily access the first > RX about 25 miles out. > Since adding the second RX, I can only access either > one about 12-15 miles > out. I simply put a "tee" connector on the > polyphaser and connected both > lines to it. Not the best engineering practice, but > I have gotten away with > it before. Does anyone have an idea about how to > properly match two > receivers to one antenna? The receivers are located > in different racks in > different parts of the building. I know Motorola and > GE had passive devices > to do this job. Is there a way to build something > "homebrew" to do this > job? TIA, and 73, > > Kevin, K9HX > You will usually get a 3 dB loss (or more) by using a tee or a normal splitter. The Mot 2 RX combiner was designed for 2 RX at somewhat removed frequencies. It had 2 tuned circuits, which reduced the loss, so it depends on how far apart your two RX's are. If you have a good preamp, you can usually put the splitter after that, and see very little loss, since most pre-amps have more than sufficient gain. Another cheap splitter is a tee with a QW section of 75 ohm cable on both legs. From the end of each QW, attach your 50 ohm cable to the individual RX's. This works very well if your RX impedences are close to 50 ohms. You can also measure the sensitivity at the input to the splitter, and right at each RX input, to see what your overall loss is. If it's much more than 4 dB or so, you might check out all the components. Joe __ Do you Yahoo!? Yahoo! Mail is new and improved - Check it out! http://promotions.yahoo.com/new_mail Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] 2 UHF receivers, one antenna
Kevin Berlen wrote: >Over the weekend, I added a second UHF control receiver at one of the sites >I take care of. The control RX antenna is up about 150ft. Previous to >adding the new RX, I could easily access the first RX about 25 miles out. >Since adding the second RX, I can only access either one about 12-15 miles >out. I simply put a "tee" connector on the polyphaser and connected both >lines to it. Not the best engineering practice, but I have gotten away with >it before. Does anyone have an idea about how to properly match two >receivers to one antenna? The receivers are located in different racks in >different parts of the building. I know Motorola and GE had passive devices >to do this job. Is there a way to build something "homebrew" to do this >job? TIA, and 73, > If you are working with just receivers, and are lucky enough not to have a bunch of RF coming down the coax, I have had good success in using a simple CATV splitter. Kevin Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] 2 UHF receivers, one antenna
Over the weekend, I added a second UHF control receiver at one of the sites I take care of. The control RX antenna is up about 150ft. Previous to adding the new RX, I could easily access the first RX about 25 miles out. Since adding the second RX, I can only access either one about 12-15 miles out. I simply put a "tee" connector on the polyphaser and connected both lines to it. Not the best engineering practice, but I have gotten away with it before. Does anyone have an idea about how to properly match two receivers to one antenna? The receivers are located in different racks in different parts of the building. I know Motorola and GE had passive devices to do this job. Is there a way to build something "homebrew" to do this job? TIA, and 73, Kevin, K9HX Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] Re: Astron Supply Help
A one ounce tube ... maybe. Yup, via Motorola ... if it is still available. Neil Mark Holman wrote: > > Say Neil how is that stuff compared to other brands ? > > also how big is the tube ? 1 Oz. or size of a tube of toothpaste ? > > apparently I am guessing order thru Motorola for that one . > > MH > - Original Message - > From: "Neil McKie" <[EMAIL PROTECTED]> > To: > Sent: Thursday, September 02, 2004 6:32 PM > Subject: Re: [Repeater-Builder] Re: Astron Supply Help > > > > > The white goop I use comes in a blue and white box with a > > Motorola Part Number, 11-83166A01, on it. > > > > Neil - WA6KLA > > > > > > Mike WA6ILQ wrote: > > > > > > At 08:40 AM 9/2/04, Tedd Doda, VE3TJD wrote: > > > > > > >On Thu, 02 Sep 2004 11:35:29 -0400, Jim B. wrote: > > > > > > > > >umm-heat sink "grease" (thermal compound) is not clear. > > > > > > > >It can be. The common stuff is white, but I've seen > > > >the clear variation on lots of industrial equipment > > > >(DC-DC motor controllers for example) used for their > > > >FET's and SCR's. > > > > > > Do you, by chance, have a manufacturer's name? > > > product info (i.e. product name, part number)? > > > Is one known to work better then the other? > > > > > > Mike WA6ILQ > > > > > > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > > > > > > > > > > > > Yahoo! Groups Links > > > > Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
[Repeater-Builder] Re: info on freg. band
Click here for a nifty spectrum chart http://www.ntia.doc.gov/osmhome/allochrt.pdf Henry > does any one know what uses the 1,300.000 freg band? have a customer that wants a scanner and thinks that is the place to go? any thoughts? > > thanks John Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/Repeater-Builder/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
Re: [Repeater-Builder] info on freg. band
Tell him it's a waste of money and is really a dead band, nobody to my knowledge would even use it except for digital stuff MAYBE ! most of the commercial stuff as to voice is the Plain Old Simple LOW, High, UHF, and 800 Mhz. Celluar is illeagle and some even said its really nonsense anyway who cares if John Doe does not use deodrant from last nights party ( but most of them talk about stuff that is nonsense anyway ) , etc.. MH - Original Message - From: Maire Company To: Repeater-Builder@yahoogroups.com Sent: Saturday, September 04, 2004 4:53 PM Subject: [Repeater-Builder] info on freg. band does any one know what uses the 1,300.000 freg band? have a customer that wants a scanner and thinks that is the place to go? any thoughts? thanks John Yahoo! Groups Links To visit your group on the web, go to:http://groups.yahoo.com/group/Repeater-Builder/ To unsubscribe from this group, send an email to:[EMAIL PROTECTED] Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
