First of all, there are other people on this list that are more qualified than I am regarding the use of a spectrum analyzer.
That said, you are looking to see only one large spike come up on your frequency when you turn the transmitter on. If you see a whole bunch of spikes (more than one, I suppose, could be several) come up at the same time, you've got a problem with either the exciter of the PA. Chuck WB2EDV ----- Original Message ----- From: "Mathew Quaife" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Tuesday, January 25, 2005 6:58 AM Subject: RE: [Repeater-Builder] Repeater Rx is Better than TX, Why > > Ok, well if I set me service monitor up on the transmitter, put my > selectivity to 20dBm, and the display to 10Db, what should I be looking > for > on the spectrum analyzer. I'm getting the manual out now to see if it > gives > instructions on transmitter testing. > > Mathew > > > -----Original Message----- > From: Chuck Kelsey [mailto:[EMAIL PROTECTED] > Sent: Tuesday, January 25, 2005 3:41 AM > To: [email protected] > Subject: Re: [Repeater-Builder] Repeater Rx is Better than TX, Why > > > You need to check the entire transmitter, not just the exciter. > > Chuck > WB2EDV > > > > ----- Original Message ----- > From: "Mathew Quaife" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Tuesday, January 25, 2005 2:17 AM > Subject: RE: [Repeater-Builder] Repeater Rx is Better than TX, Why > > >> >> Well have to rule out the wattmeter, I have two of them, both gave the >> same >> results, one being bird wattmeter and the other being Yaesu YS-500. The >> antenna has only been in-service since September. If it was the antenna, >> would it not be noticed on the RX as well, which is not having any >> problems >> at all. I will put the exciter back on the scope today and look at it, >> but >> last I looked it was fine. Someone mentioned my past problem with >> adjacent >> channel noise, yes, there was a problem there, the deviation had jumped >> up >> to over 6 Khz wide, brought it back down to 4.5 Khz via the controller >> and >> that took care of that. Will pump the signal into the service monitor >> and >> see what that reads. All I know it seems strange for it to receive twice >> as >> far as it does transmit. >> >> Mathew >> >> >> -----Original Message----- >> From: Mike Morris WA6ILQ [mailto:[EMAIL PROTECTED] >> Sent: Monday, January 24, 2005 3:41 PM >> To: [email protected] >> Subject: Re: [Repeater-Builder] Repeater Rx is Better than TX, Why >> >> >> Either your wattmeter is lying, or you have one of two >> worse problems.. >> >> 1) >> Check your TX with a spectrum analyzer. I'll bet that >> your on-frequency power is down. >> A wattmeter reads power on all frequencies - spurs or >> on frequency. >> >> I was bit by that oversight years ago. >> >> A 6m 100w TX that used to be clean ended up as a comb >> generator due to a leak in the roof creating corrosion in >> the PA deck... The on-channel power was maybe 20w, >> everything else was trash. >> >> It was a miracle that we caught it before someone else >> figured out where the grunge was coming from. >> >> 2) >> Your diamond antenna may be hosed and giving you a >> low ERP. >> >> Mike WA6ILQ >> >> At 03:28 PM 1/24/05, you wrote: >> >>>Ok, I know this sounds silly, but my repeater is now hearing >>>better than it transmits. Here's the setup, the the issue. I have >>>a Maggorie (no comments) HiPro transmiitter running 2 watts into >>>a Vocom Amp running 160 Watts into the duplexer, 130 out to the >>>antenna, fed with 7/8" hardline into a Diamond Dual Band Antenna >>>at 92'. VSWR is 1.1:1, with 130 watts forward and 1/10 watt reflected >>>at an impedance of 52 ohms, (MJF 259). >>> >>>The receiver is a GE Mastr Pro ER-41 series receiver, tied to an ARR >>>preamp at 24 db going through a two of the DB 4001-1 for filtering >>>and finally into a set of TX-RX Duplexers, 3 cans pers side. >>> >>>I used to be able to hear the repeater nearly full scale for about >>>40 miles with no problem. Recently at 20 miles away, it's barely at >>>1/4 scale on my radio. This has been noticable with several users >>>on the system, and my mobile just got a new antenna, all set and >>>tested fine there, and other repeaters there is no problem. I can >>>hear users nearly 60 miles from the repeater, but they can't hear >>>the system. >>> >>>Is it possible something could be wrong on the duplexer end of it. >>>I get no decense on the system, and receive audio is ok quality at >>>60 miles, just less than full quieting. >>> >>>Any thoughts. Mybe just propagation. >>> >>>And the 160 watts from the Vocom amp was as low as I could go before >>>I began to cause havick, so it does not like lower power. >>> >>>Mathew Thanks! >> >> >> >> >> >> >> Yahoo! Groups Links >> >> >> >> >> >> >> >> >> >> >> >> >> Yahoo! Groups Links >> >> >> >> >> >> >> >> > > > > > > > > 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/
