RE: [Repeater-Builder] Duplexers
My statement regarding "tuning" did not explicitly refer to the actual tuning of the duplexer, but to the matching of the TX and duplexer in combination. This can be proven if two Birds are used, one between the TX and the duplexer input and the other between the duplexer output and the antenna. In the majority of cases I have witnessed, adding a Bird between the TX and the duplexer will cause the forward power shown on the other Bird to change significantly. To avoid the misunderstanding, perhaps I should have used the term impedance match. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Jeff DePolo Sent: Friday, August 24, 2007 9:30 PM To: Repeater-Builder@yahoogroups.com Subject: RE: [Repeater-Builder] Duplexers > When you put the Bird between the TX and the duplexer, you > have changed the > length of the jumper cable, which upset the tuning. Adding a wattmeter or any other length of cable between the transmitter and the duplexer Tx input port has no effect on the tuning of the duplexer. It may change the load Z the transmitter sees, which may make the transmitter happier (or sadder) depending on the resulting Z, but in no way does it alter the tuning of the duplexer itself. Adding or removing cable lengths between the transmitter and duplexer also does not change the VSWR as seen by the transmitter (minimal cable loss effects notwithstanding). --- Jeff
RE: [Repeater-Builder] Duplexers
> When you put the Bird between the TX and the duplexer, you > have changed the > length of the jumper cable, which upset the tuning. Adding a wattmeter or any other length of cable between the transmitter and the duplexer Tx input port has no effect on the tuning of the duplexer. It may change the load Z the transmitter sees, which may make the transmitter happier (or sadder) depending on the resulting Z, but in no way does it alter the tuning of the duplexer itself. Adding or removing cable lengths between the transmitter and duplexer also does not change the VSWR as seen by the transmitter (minimal cable loss effects notwithstanding). --- Jeff - Jeff DePolo - [EMAIL PROTECTED] Broadcast Sciences LLC, Valley Forge PA v: 610.917.3000 f: 610.917.3030
RE: [Repeater-Builder] Duplexers
--- Eric Lemmon <[EMAIL PROTECTED]> wrote: > Bernie, > > When you put the Bird between the TX and the > duplexer, you have changed the > length of the jumper cable, which upset the tuning. > But, really, you need > not worry about what the SWR is, if the forward > power to the antenna is > appropriate. > > Let's say you have a 4-can duplexer, which might > have about 1.5 dB insertion > loss. If your power amp delivers exactly 100 watts > into a dummy load when > connected directly at the TX output, you should > expect about 70 watts going > to the antenna when the duplexer is in the circuit. > A 6-can duplexer might > have about 2.2 dB insertion loss, and you should see > about 59 watts going to > the antenna. > > 73, Eric Lemmon WB6FLY > > When the wattmeter is inserted it will not upset the tuning of the duplexer enough to reflect that kind of power. About all it could do is upset the tuning of the transmitter so that it will not put out the same ammount of forward power. This should not have much effect of the reflected power. One thing that could be (but not likely) is the transmitter is producing spurs and harmonices the duplexer is not letting pass to the antenna and is being reflected back. Boardwalk for $500? In 2007? Ha! Play Monopoly Here and Now (it's updated for today's economy) at Yahoo! Games. http://get.games.yahoo.com/proddesc?gamekey=monopolyherenow
RE: [Repeater-Builder] Duplexers
Bernie, When you put the Bird between the TX and the duplexer, you have changed the length of the jumper cable, which upset the tuning. But, really, you need not worry about what the SWR is, if the forward power to the antenna is appropriate. Let's say you have a 4-can duplexer, which might have about 1.5 dB insertion loss. If your power amp delivers exactly 100 watts into a dummy load when connected directly at the TX output, you should expect about 70 watts going to the antenna when the duplexer is in the circuit. A 6-can duplexer might have about 2.2 dB insertion loss, and you should see about 59 watts going to the antenna. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of dallasreact112 Sent: Friday, August 24, 2007 5:16 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Duplexers Anyone one know what to expect SWR wise with a duplexer? I have a DB products 2 meter duplexer on an amateur repeater. Measuring with a Bird wattmeter between the duplexer and antenna I read 50W forward and a couple watts reverse. That is ok. But when I check between the transmitter and the TX port on the duplexer I get a about 60 W forward and 25W reverse power. Is there a rule fo thumb for a known good SWR value thru a duplexer? Should a good duplexer introduce any significant SWR? Thanks Bernie Parker K5BP
Re: [Repeater-Builder] Duplexers
Bernie, A typical VSWR for a duplexer would be 1.5:1 or less, more like less. Will not be 1:1 most times, but low. A lot lower than your 65/25W which is more like a 4.5:1 VSWR. Really sounds as the duplexer is out of tune or has an internal problem. Wonder if you tuned these from another band such as 150-160 down to 144-148. Did you keep the upper freq on the same side and the lower on the new lower??? Often one should keep the same even if the upper/lower is say tx/rx and the new is upper/lower rx/tx. Not always, but have seen a problem if one tries to reverse the cavity sides, make upper side the lower freq just because one says tx and the other rx and try to keep on same side, but reverse the upper/lower. This is getting confusing, hi. 73, ron, n9ee/r >From: dallasreact112 <[EMAIL PROTECTED]> >Date: 2007/08/24 Fri PM 07:16:22 CDT >To: Repeater-Builder@yahoogroups.com >Subject: [Repeater-Builder] Duplexers > >Anyone one know what to expect SWR wise with a duplexer? >I have a DB products 2 meter duplexer on an amateur repeater. >Measuring with a Bird wattmeter between the duplexer and antenna I >read 50W forward and a couple watts reverse. That is ok. But when I >check between the transmitter and the TX port on the duplexer I get a >about 60 W forward and 25W reverse power. Is there a rule fo thumb for >a known good SWR value thru a duplexer? Should a good duplexer introduce >any significant SWR? > >Thanks > >Bernie Parker > >K5BP > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
Re: [Repeater-Builder] Duplexers
>From the Dup. to the Ant. is ok. But the Dup. is out of tune or no good. Might >even be a bad jumper on the Dup. dallasreact112 <[EMAIL PROTECTED]> wrote: Anyone one know what to expect SWR wise with a duplexer? I have a DB products 2 meter duplexer on an amateur repeater. Measuring with a Bird wattmeter between the duplexer and antenna I read 50W forward and a couple watts reverse. That is ok. But when I check between the transmitter and the TX port on the duplexer I get a about 60 W forward and 25W reverse power. Is there a rule fo thumb for a known good SWR value thru a duplexer? Should a good duplexer introduce any significant SWR? Thanks Bernie Parker K5BP Yahoo! Groups Links
Re: [Repeater-Builder] Duplexers
If the duplexer is correctly tuned, there will be NO measurable SWR into it. If you have 25/60 watts, it is way off frequency. - Original Message - From: dallasreact112 To: Repeater-Builder@yahoogroups.com Sent: Friday, August 24, 2007 7:16 PM Subject: [Repeater-Builder] Duplexers Anyone one know what to expect SWR wise with a duplexer? I have a DB products 2 meter duplexer on an amateur repeater. Measuring with a Bird wattmeter between the duplexer and antenna I read 50W forward and a couple watts reverse. That is ok. But when I check between the transmitter and the TX port on the duplexer I get a about 60 W forward and 25W reverse power. Is there a rule fo thumb for a known good SWR value thru a duplexer? Should a good duplexer introduce any significant SWR? Thanks Bernie Parker K5BP
Re: [Repeater-Builder] Duplexers
Generally the duplexer only makes a slight contribution to the reflected power. How doe the reflected power between the transmitter and antenna, without the duplexer in line look? Steve NU5D dallasreact112 wrote: > Anyone one know what to expect SWR wise with a duplexer? > I have a DB products 2 meter duplexer on an amateur repeater. > Measuring with a Bird wattmeter between the duplexer and antenna I > read 50W forward and a couple watts reverse. That is ok. But when I > check between the transmitter and the TX port on the duplexer I get a > about 60 W forward and 25W reverse power. Is there a rule fo thumb for > a known good SWR value thru a duplexer? Should a good duplexer introduce > any significant SWR? > > Thanks > > Bernie Parker > > K5BP > > > > > > > Yahoo! Groups Links > > > > >
[Repeater-Builder] Duplexers
Anyone one know what to expect SWR wise with a duplexer? I have a DB products 2 meter duplexer on an amateur repeater. Measuring with a Bird wattmeter between the duplexer and antenna I read 50W forward and a couple watts reverse. That is ok. But when I check between the transmitter and the TX port on the duplexer I get a about 60 W forward and 25W reverse power. Is there a rule fo thumb for a known good SWR value thru a duplexer? Should a good duplexer introduce any significant SWR? Thanks Bernie Parker K5BP
Re: [Repeater-Builder] Spectrum Repeater CW ID 'er Bipolar Prom
Comm Spec sells a programmable CW ID for about $60. However, what is the PROM...part number. I might have a programmer for it. Might even have the PROM. 73, ron, n9ee/r >From: skipp025 <[EMAIL PROTECTED]> >Date: 2007/08/24 Fri PM 12:53:33 CDT >To: Repeater-Builder@yahoogroups.com >Subject: [Repeater-Builder] Spectrum Repeater CW ID 'er Bipolar Prom > >Spectrum Repeater CW ID'er Bipolar Prom > >> If the IDer has a PROM then little can and should be done >> to go another way...a new PROM. > >Spectrum sells a replacement prom from about $55, which is kind >of out of line for a price... but at least it's available. > >You can find/ask someone with a bipolar prom burner to make a new >chip for you. But you have to find the chip and figure out how >to map your call sign into the new part. > >One can also replace a Prom with an Eprom using a small adapter >daughterboard, which is a path I've used many times. You need >only have the eprom, programmer and set up the programming. > >Prom daughter/adapter boards run under $20 each... > >Another option would be to disable the factory ID'er and >install an ID-O-Matic or similar ID unit. > >cheers, >skipp > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
Re: [Repeater-Builder] Spectrum Repeater CW ID 'er Bipolar Prom
At 10:53 AM 8/24/2007, you wrote: >You can find/ask someone with a bipolar prom burner to make a new >chip for you. <---I had a bipolar prom burner but it committed suicide a few years back. Its therapist said had I only paid attention to its cries out for help, this tragedy might have been averted Ken
[Repeater-Builder] Spectrum Repeater CW ID 'er Bipolar Prom
Spectrum Repeater CW ID'er Bipolar Prom > If the IDer has a PROM then little can and should be done > to go another way...a new PROM. Spectrum sells a replacement prom from about $55, which is kind of out of line for a price... but at least it's available. You can find/ask someone with a bipolar prom burner to make a new chip for you. But you have to find the chip and figure out how to map your call sign into the new part. One can also replace a Prom with an Eprom using a small adapter daughterboard, which is a path I've used many times. You need only have the eprom, programmer and set up the programming. Prom daughter/adapter boards run under $20 each... Another option would be to disable the factory ID'er and install an ID-O-Matic or similar ID unit. cheers, skipp
[Repeater-Builder] Re: MSR 2000
> The MSR2000 has a terrible carrier squelch. I strongly suggest > anyone running a MSR2000 to integrate a Link-Comm RLC-MOT (Micor) > squelch board. Nothing wrong with the MSR-2000 repeater in carrier squelch. I've found most people don't clearly understand how to connect, configure and adjust their controllers for MSR CSQ operation. My carrier squelch MSR-2000 repeaters sound just a clean and quiet (no crash heard) using the stock equipment. The Micor Audio Squelch board path (regardless of mfgr) is a nice way to go if you don't already have the hardware resources in place. The MSR-2000 has the hardware resources in place... one does not really have to be redundant. > Compared to the Micor, the MSR2000 was a short-lived product > line. Which can be said about most other repeater/base mfgr brands and models. Long lived repeater (specific) models will no longer be possible regardless of the product quality. cheers, s.
[Repeater-Builder] Re: WANTED....power control board.
Easier to buy the entire pa from an Ebay Auction. If you have some time, a pot of coffee and the XM-150 playing low inthe background you can trouble shoot the power control board easy enough. Not a lot of fun... but it can be done... cheers, skipp > "Pete Theo" <[EMAIL PROTECTED]> wrote: > > For the MSR 2000.Part TLD 9272 A or the whole PA.Part for the PA TLD > 2532A.Price? >
[Repeater-Builder] Wanted for experimentation purposes
Anyone have any spare SEA ESP504 or ESP520 radios avalible cheap? I would also like the ESP700 later down the road.
Re: [Repeater-Builder] Re: Micor Repeater Low Current Mods
I agree with Ron, an attenuator will present the correct load to the exciter. Kevin Ron Wright wrote: > It might work, but for how long. Also detuning the cavity might upset the > loading making the exciter unhappy. This can cause many RF problems > including spurious generation. > > I would consider building a 16 db antenuator. > > 73, ron, n9ee/r > >> How about this then: in the micor there is a 4 cavity filter on theoutput of >> the exciter. If I tuned 3 of those cavities properly and detuned the last >> so it acts as an -16 dB attenuator would that work in obtaining my 10 mW >> input into my mobile amp without creating any problems? > >
Re: [Repeater-Builder] Spectrum Communications SCR 77 UHF repeater
Hi Tim, Looking at our S-7R manual about the optional CWID, it is factory programmed. We use the id from our controller as the id source. Russ AE6UX wd4chs <[EMAIL PROTECTED]> wrote: I am in need of or someone who knows anything about the CWID for a Spectrum SCR-77 UHF repeater. The CWID it has now functions good only it is not my call. From what I have read about this CWIDer you have to have the manufacturer "burn" a chip for you that plugs into the board. Is there any other way? Thanks, Tim WD4CHS
[Repeater-Builder] TETRA Motorola MTP 700
Hi everyone. Anyone knows something about programming Direct Mode Freq in the Motorola MTP 700 TETRA radio? Does anyone have the RSS? Thanks.
[Repeater-Builder] Motorola GR 900 Repeater.
Hi. Need all the help and info i can get about this repeater. PIN- connection on the back specifick. Thanks.
Re: Re: [Repeater-Builder] Re: Micor Repeater Low Current Mods
It might work, but for how long. Also detuning the cavity might upset the loading making the exciter unhappy. This can cause many RF problems including spurious generation. I would consider building a 16 db antenuator. 73, ron, n9ee/r >From: Jesse Lloyd <[EMAIL PROTECTED]> >Date: 2007/08/24 Fri AM 12:13:00 CDT >To: Repeater-Builder@yahoogroups.com >Subject: Re: [Repeater-Builder] Re: Micor Repeater Low Current Mods > >How about this then: in the micor there is a 4 cavity filter on theoutput of >the exciter. If I tuned 3 of those cavities properlyand detuned the last so >it acts as an -16 dB attenuator would that workin obtaining my 10 mW input >into my mobile amp without creating anyproblems? > > > >On 8/23/07, Kevin Custer <[EMAIL PROTECTED]> wrote: >Jesse, > >While your method may work, it likely won't be clean; not ever a goodthing, >especially where a repeater transmitter is concerned. The MicorVHF >transmitter, like most FM transmitters, uses Class C RFamplification. When a >Class C amplifier is under-driven, or turneddown below about 50 or 60% of its >capability, it can become unstable -spurious. It is much better to select >the number of stages, andproperly drive them to create the amount of power >output required. This also results in the best efficiency, and since you >won't haveexcess power to burn in a solar situation, the method I suggest >islikely better. > >Jesse Lloyd wrote:That PA mod is awesome. I was considering knocking downthe >power outof the exciter to 20 mW by increasing the value of a couple >resistors,and then feeding it into a 40 Watt M100 PA. From there I have >theability to vary the output power from 5-40 watts (ish). > >Jesse > > > > On 8/22/07, Kevin Custer <[EMAIL PROTECTED]> wrote: >Jesse, > >You can put a toggle switch on the B+ line going to the Audio PA, thiswill cut >several hundred mA of current draw from the Class AB audiosection, and allow >it to be connected/turned on when service isrequired. > >Since you are working on a VHF unit, you can review the mods on thissite where >I took a 110 watt PA, hack-sawed it in half, and made a 5 to12 watt PA that is >very power efficient: >http://www.kuggie.com/ahra/hmftinfo.html > >I've also been successful in doing the same with only one transistor(the >controlled stage) and created a .5 to 2 watt PA. > > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
