Re: [Repeater-Builder] Re: Amplifier
Dear Gary, Thanks for the calculations. As we are using a +22dBm amplifier, the output per channel shall work out as -2dBm (+22dBm - 24dB, and +22dBm is 1dB compression point). However, the measurement shows that it is -24dBm per channel. Anything we have missed out? Best Regards, Chong Kwan Meng - Original Message From: Gary Schafer [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Friday, 11 January 2008 2:28:09 Subject: RE: [Repeater-Builder] Re: Amplifier If you want each signal, of the 16 signals, to be 0 dBm (1 mW) output capable then the amplifier has to be capable of 16 squared times 1 mW or 256 milliwatts. This is the peak envelope power that can be present at any one time in the amplifier with 16 signals present. So the amplifier would need to be able to handle a little over +24dBm with a single signal (256mW) With only 2 signals of 1 mW each the peak envelope power would be 2 squared (2x2) or 4 mW that the amplifier would need to handle or +6dBm. It is the number of signals squared times the power of one of the signals assuming that all the signal levels are the same. This is exactly the same thing as if it was an SSB linear amplifier and you were testing it with multiple tones. 73 Gary K4FMX From: Repeater-Builder@ yahoogroups. com [mailto:Repeater- [EMAIL PROTECTED] ups.com] On Behalf Of Kent Chong Sent: Thursday, January 10, 2008 8:46 PM To: Repeater-Builder@ yahoogroups. com Subject: Re: [Repeater-Builder] Re: Amplifier Dear NJ902, Thanks for your advise. In this case, what is the amplifier power rating for us to obtain 0dBm output power for 16 channels? Best Regards, Chong Kwan Meng - Original Message From: nj902 [EMAIL PROTECTED] net To: Repeater-Builder@ yahoogroups. com Sent: Friday, 11 January 2008 12:23:19 Subject: [Repeater-Builder] Re: Amplifier It appears that your amplifier is doing what you should expect. An amplifier's power handling capability, compression point, etc. are rated based on amplification of a single sinusoid. When multiple signals are present at the amplifier input, the total output power of the amplifier does not change, hence the power available per channel decreases as the number of input signals increases. Also, since multiple independent signals will combine randomly, crest factor issues further decrease the available power per channel in order to keep the amplifier output below clipping. This is a common issue in the design of signal enhancement products such as BDA's used to provide coverage extension for trunking and cellular radio systems. - - - - - - --- In Repeater-Builder@ yahoogroups. com, Kent Chong kentchongkm@ ... wrote: All three amplifiers are connected in series. I shall correct my statement: in the lab, we get 0dBm output on the last stage of amplifier. However, when we are at the site, it max at -24dBm (it is - ve, sorry). There is no difference in the configuration but number of channel. Tired of visiting multiple sites for showtimes? Yahoo! Movies is all you need __ Search, browse and book your hotels and flights through Yahoo! Travel. http://sg.travel.yahoo.com
RE: [Repeater-Builder] Re: Amplifier
Hi Chong, I am not exactly sure what the equipment is being used for? Is this a receive amplifier or for transmitters? How much power output do you get with just one signal applied to the amplifier? Will it produce +22dBm with one signal if the input level is increased? What is the gain of the amplifier? How many dB? Are you sure that the amplifier has capability to actually produce +22dBm of signal or is it speced at +22dBm 3rd order intercept point at 1 dB compression? If that is the case you will never see +22dBm out of it as the 3rd order intercept spec is only a theoretical projection point. You mentioned in an earlier post that you had 3 amplifiers in series. Is that still the case? What is the gain of each amplifier by itself? What is the power output capability of each amplifier? Are these receiver preamplifiers? 73 Gary K4FMX _ From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Kent Chong Sent: Friday, January 11, 2008 3:55 AM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: Amplifier Dear Gary, Thanks for the calculations. As we are using a +22dBm amplifier, the output per channel shall work out as -2dBm (+22dBm - 24dB, and +22dBm is 1dB compression point). However, the measurement shows that it is -24dBm per channel. Anything we have missed out? Best Regards, Chong Kwan Meng - Original Message From: Gary Schafer [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Friday, 11 January 2008 2:28:09 Subject: RE: [Repeater-Builder] Re: Amplifier If you want each signal, of the 16 signals, to be 0 dBm (1 mW) output capable then the amplifier has to be capable of 16 squared times 1 mW or 256 milliwatts. This is the peak envelope power that can be present at any one time in the amplifier with 16 signals present. So the amplifier would need to be able to handle a little over +24dBm with a single signal (256mW) With only 2 signals of 1 mW each the peak envelope power would be 2 squared (2x2) or 4 mW that the amplifier would need to handle or +6dBm. It is the number of signals squared times the power of one of the signals assuming that all the signal levels are the same. This is exactly the same thing as if it was an SSB linear amplifier and you were testing it with multiple tones. 73 Gary K4FMX _ From: Repeater-Builder@ yahoogroups. com [mailto:Repeater- [EMAIL PROTECTED] ups.com] On Behalf Of Kent Chong Sent: Thursday, January 10, 2008 8:46 PM To: Repeater-Builder@ yahoogroups. com Subject: Re: [Repeater-Builder] Re: Amplifier Dear NJ902, Thanks for your advise. In this case, what is the amplifier power rating for us to obtain 0dBm output power for 16 channels? Best Regards, Chong Kwan Meng - Original Message From: nj902 [EMAIL PROTECTED] net To: Repeater-Builder@ yahoogroups. com Sent: Friday, 11 January 2008 12:23:19 Subject: [Repeater-Builder] Re: Amplifier It appears that your amplifier is doing what you should expect. An amplifier's power handling capability, compression point, etc. are rated based on amplification of a single sinusoid. When multiple signals are present at the amplifier input, the total output power of the amplifier does not change, hence the power available per channel decreases as the number of input signals increases. Also, since multiple independent signals will combine randomly, crest factor issues further decrease the available power per channel in order to keep the amplifier output below clipping. This is a common issue in the design of signal enhancement products such as BDA's used to provide coverage extension for trunking and cellular radio systems. - - - - - - --- In Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups. com, Kent Chong kentchongkm@ ... wrote: All three amplifiers are connected in series. I shall correct my statement: in the lab, we get 0dBm output on the last stage of amplifier. However, when we are at the site, it max at -24dBm (it is - ve, sorry). There is no difference in the configuration but number of channel. _
RE: [Repeater-Builder] Cavity Duplexer
Wayne, RG-55/U coaxial cable might not be your best choice. That cable came into being more than a half-century ago, as MIL-C-17/26, and was canceled late in 1969. The RG-55B/U had two silver-plated copper braid shields, a solid polyethylene dielectric, and a solid copper center conductor that was silver-plated. It had a HMW polyethylene jacket. Be very careful that you do not confuse RG-55A/U with RG-55B/U cable. The B version has double tinned-copper shields in place of the A version's silver-coated copper shields. In 1969, RG-55B/U was officially replaced with MIL-C-17/84, also known as RG-223/U. In mid-1993, RG-223/U was declared inactive for new designs, and its replacement was MIL-C-17/194, also known as M17/194-1. Unfortunately, the current specification for MIL-C-17/194B calls for a one-mil polyester barrier tape that has an aluminum layer in contact with the outer shield. Some users of this latest version have reported that the aluminum/silver junction is a potential noise source, so keep that in mind, My choice for jumper cables on a cavity duplexer is RG-400/U, not to be confused with the LMR-400 cable. RG-400/U has a stranded copper center conductor that is silver-coated. It has Teflon dielectric, two silver-coated copper braid shields, and an FEP jacket. It looks and performs exactly the same as RG-142/U cable, except that the latter has a solid steel center conductor. There are several Internet sites that sell RG-400/U cable by the foot. I also suggest using silver-plated crimp-type connectors, rather than nickel-plated connectors, to avoid intermodulation problems. Jumper cable at the duplexer should be completely free of dissimilar-metal joints, for best performance. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of vk4cya Sent: Thursday, January 10, 2008 1:22 AM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] cavity duplexer Hello to the group, I have just joined the group. The local radio club that I'm in is putting together a cavity duplexer a lot like the one in the July 1972 issue of QST. We are going ahead leaps and bounds but we have came across a problem. It is suggested that we use RG55/U coax on the cavities, but the problem is that I can't find anyone in Australia selling that type of coax. So, is there anyone that could help me in suggesting what else could be used? I have found a couple of sites on the net that have RG55/U but in roll form. We are looking for around 2 metres of it only. Any help would be most great Thanks Wayne vk4cya
[Repeater-Builder] Need Power Amp Transistors for VHF 125 watt MSF-5000 repeater
Need Power Amp Transistors for VHF 125 watt MSF-5000 repeater, part number 33P60. Can anyone help? Kent W7AOR www.narri.org Please e-mail w7aor@ narri.org
[Repeater-Builder] Re: Need Power Amp Transistors for VHF 125 watt MSF-5000 repeater
--- In Repeater-Builder@yahoogroups.com, Kent [EMAIL PROTECTED] wrote: GOGGLE THE PART NUMBER many out there.. Need Power Amp Transistors for VHF 125 watt MSF-5000 repeater, part number 33P60. Can anyone help? Kent W7AOR www.narri.org Please e-mail w7aor@ narri.org
RE: [Repeater-Builder] Need Power Amp Transistors for VHF 125 watt MSF-5000 repeater
The transistor you seek is Motorola Part Number 4882233P60, described as MOSFET_SRFM33P60 and priced at $154.40 each. Although I don't have a commercial equivalent number for you, I believe that a careful perusal of an older Motorola RF Device Data Book will reveal the commercial equivalent. I don't think it would be in Motorola's best interests to manufacture a unique device that had limited usage, just for mobile and station power amplifiers. No doubt the 33P60 is simply a selected part with close tolerances, so that it can be paralleled in certain applications. That practice is of modest benefit in single-ended PAs. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Kent Sent: Friday, January 11, 2008 12:40 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Need Power Amp Transistors for VHF 125 watt MSF-5000 repeater Need Power Amp Transistors for VHF 125 watt MSF-5000 repeater, part number 33P60. Can anyone help? Kent W7AOR www.narri.org Please e-mail w7aor@ narri.org
[Repeater-Builder] 2000 foot tower falls in Little Rock - Any ham repeaters there?
http://www.arkansasbusiness.com/article.aspx?aID=102174.87444.114316
[Repeater-Builder] Re: Genesis series questions
I wanted to thank those that have replied and helped me out with these questions. I realize they are a little off topic but I found this group through the repeater builder website so I thought it wouldn't hurt to ask. Further, if you don't mind, I have developed a related question. I have further researched the repeater builder website and found the mod to reduce the trickle charge rate of the desk top charger. Since the desktop charger circuit and and circuit of the MVA are similar does anyone know where the equatable resistor would be in the MVA. A fellow member has given me the schematics but they are just different enough for me to encounter some serious head scratching. Can anyone offer assistance? Albert KI4ORI Two questions for everyone. First off, I am trying to mod my MVA (Convertacom) to handle NiMH batteries. I have looked at the repeater-builder website and found the schematic. I opened up my MVA and there is no silk screening on the board to identify the components. I began to attempt to trace the circuit but that might take eons. So, does anyone have a picture or can tell me where R45 is located so that I might change it to the appropriate value? Actually if I could just identify which IC is labeled as U4 that would work too. I can surely find pin 9 from there. Secondly, I have run into a programming problem. I have HT600's, P200's and a newly acquired MT1000. Went to try and program the MT1000 on my 286 and received Serial Bus Access Error 003 on the screen when trying to read the radio. I checked batteries, cables, and the like and no change. I then tried to read one of my other radios that I had programed before and received the same error. So then I tried my 386 computer. Same error. I then tried a different RIB. Same error. Anyone have any ideas?
Re: [Repeater-Builder] Need Power Amp Transistors for VHF 125 watt MSF-5000 repeater
I checked RF Parts www.rfparts.com and did not see it listed but I would sure give them a call. Gran K6RIF At 12:40 PM 1/11/2008, you wrote: Need Power Amp Transistors for VHF 125 watt MSF-5000 repeater, part number 33P60. Can anyone help? Kent W7AOR www.narri.org Please e-mail w7aor@ narri.org
[Repeater-Builder] Motorola Mitrek Power Question.
Hi All, Just a quick question to confirm before proceeding to finish. I have a low band Mitrek on 10mtrs. I am using 2 radios, one for RX and one for TX. The TX is working fine, and now I am just fixing a couple of issues on the RX. I note in the manual and Mike's information the wiring for the power (voltage), noticing the 3 main wires for it, the large wire for the PA, pin 12 for TX and pin 4 for RX. Now because the radio is only going to be used in RX mode, I am wondering if I can leave the large wire (which goes to oin 17 I think) and pin 12 off and only run power to pin 4 for the RX side??? Thanks and look forward to your reply. Kevin, ZL1KFM. Get Skype and call me for free. sparc_nz Description: Binary data
[Repeater-Builder] NHRC-4 CONTROLLER AND TS-32 TONE BOARD
Hi Guys, Another project and another question for you please. I am installing a TS-32 on my UHF repeater. I followed the instructions and the decode works OK. Now I want the Encode Output to be active only when CAS is activated, so there is no ctcss present when the tail is on. I can't seem to find any logic points on the TS-32 where I can hook a simple transistor and relay to cut the encode when the decode drops. Any suggestions on how to accomplish this? 73 JIM KA2AJH
RE: [Repeater-Builder] Motorola Mitrek Power Question.
Kevin, When you are using separate radios for TX and RX, it is a good idea to perform all modifications to both radios, so that they are identical. When one radio fails, you can simply switch them and be back on the air in minutes. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Gmail - Home Sent: Friday, January 11, 2008 6:02 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Motorola Mitrek Power Question. Hi All, Just a quick question to confirm before proceeding to finish. I have a low band Mitrek on 10mtrs. I am using 2 radios, one for RX and one for TX. The TX is working fine, and now I am just fixing a couple of issues on the RX. I note in the manual and Mike's information the wiring for the power (voltage), noticing the 3 main wires for it, the large wire for the PA, pin 12 for TX and pin 4 for RX. Now because the radio is only going to be used in RX mode, I am wondering if I can leave the large wire (which goes to oin 17 I think) and pin 12 off and only run power to pin 4 for the RX side??? Thanks and look forward to your reply. Kevin, ZL1KFM
Re: [Repeater-Builder] NHRC-4 CONTROLLER AND TS-32 TONE BOARD
If you are going to use a relay, simply use a set of the relay contacts to break the encode output line. Chuck WB2EDV - Original Message - From: Jim Cicirello [EMAIL PROTECTED] To: Repeater-Builder@yahoogroups.com Sent: Friday, January 11, 2008 9:25 PM Subject: [Repeater-Builder] NHRC-4 CONTROLLER AND TS-32 TONE BOARD Hi Guys, Another project and another question for you please. I am installing a TS-32 on my UHF repeater. I followed the instructions and the decode works OK. Now I want the Encode Output to be active only when CAS is activated, so there is no ctcss present when the tail is on. I can't seem to find any logic points on the TS-32 where I can hook a simple transistor and relay to cut the encode when the decode drops. Any suggestions on how to accomplish this? 73 JIM KA2AJH Yahoo! Groups Links
Re: [Repeater-Builder] Motorola Mitrek Power Question.
Eric, Thank you for your quick reply. I would agree with you in your comments below. I should point out that I have 3x 60watt models for the RX's and 2x 110 Watters for the TX (set at 60 watts), so I have spares to swap out as required. I would hope I don't have that many failures at one time, but switching around would and could be done if required. I should of also mentioned that it is in the connector head for the RX unit that I only was looking at the RX voltage. Was thinking that if I do not need to power the TX side, why waste fitting the wires, and also the need to power it (that side)? The radios are fully modified, all the same. Thanks Kevin. Get Skype and call me for free. - Original Message - From: Eric Lemmon To: Repeater-Builder@yahoogroups.com Sent: Saturday, January 12, 2008 3:43 PM Subject: RE: [Repeater-Builder] Motorola Mitrek Power Question. Kevin, When you are using separate radios for TX and RX, it is a good idea to perform all modifications to both radios, so that they are identical. When one radio fails, you can simply switch them and be back on the air in minutes. 73, Eric Lemmon WB6FLY -Original Message- From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Gmail - Home Sent: Friday, January 11, 2008 6:02 PM To: Repeater-Builder@yahoogroups.com Subject: [Repeater-Builder] Motorola Mitrek Power Question. Hi All, Just a quick question to confirm before proceeding to finish. I have a low band Mitrek on 10mtrs. I am using 2 radios, one for RX and one for TX. The TX is working fine, and now I am just fixing a couple of issues on the RX. I note in the manual and Mike's information the wiring for the power (voltage), noticing the 3 main wires for it, the large wire for the PA, pin 12 for TX and pin 4 for RX. Now because the radio is only going to be used in RX mode, I am wondering if I can leave the large wire (which goes to oin 17 I think) and pin 12 off and only run power to pin 4 for the RX side??? Thanks and look forward to your reply. Kevin, ZL1KFM sparc_nz Description: Binary data
[Repeater-Builder] Re: Motorola Mitrek Power Question.
You only need A+ on pin 4 for the Mitrek to receive. No need for the big red wire in the receiver harness/connector.
RE: [Repeater-Builder] NHRC-4 CONTROLLER AND TS-32 TONE BOARD
Hi Chuck, Here I have explained to Lowell the problem I am having using a relay to break the encode output line: Any ideas Hi Lowell, Thanks for the information. I have a similar design I think where I use the COS to turn on a transistor that operates a relay that the encoder goes through. My problem is that after a CTCSS Signal activates the NHRC-4, any interference or signals on the frequency can come thru the tail. Now those signals are not transmitting CTCSS but the repeater is repeating them with carrier squelch as long as the tail is up. Once the tail drops, it stops until a CTCSS Signal opens the controller and again the tail will transmit the signal. Have you experienced this? It appears that I need to take the COS signal from the DECODER so when the DECODER drops, the controller will MUTE the tail. Possibly I have problem with the controller not muting. Any ideas? Here is an example: I put the service monitor on the MASTR II and transmit a carrier without CTCSS. Nothing happens. I apply the 107.2 tone and the controller comes active and re-transmits the signal OK. I stop the CTCSS tone from the generator and let the carrier transmit and the repeater tail will transmit the noise from the generator for the duration of the tail. Thanks JIM _ From: Repeater-Builder@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Chuck Kelsey Sent: Friday, January 11, 2008 9:57 PM To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] NHRC-4 CONTROLLER AND TS-32 TONE BOARD If you are going to use a relay, simply use a set of the relay contacts to break the encode output line. Chuck WB2EDV - Original Message - From: Jim Cicirello [EMAIL PROTECTED] mailto:ka2ajh%40gmail.com com To: Repeater-Builder@ mailto:Repeater-Builder%40yahoogroups.com yahoogroups.com Sent: Friday, January 11, 2008 9:25 PM Subject: [Repeater-Builder] NHRC-4 CONTROLLER AND TS-32 TONE BOARD Hi Guys, Another project and another question for you please. I am installing a TS-32 on my UHF repeater. I followed the instructions and the decode works OK. Now I want the Encode Output to be active only when CAS is activated, so there is no ctcss present when the tail is on. I can't seem to find any logic points on the TS-32 where I can hook a simple transistor and relay to cut the encode when the decode drops. Any suggestions on how to accomplish this? 73 JIM KA2AJH Yahoo! Groups Links
