Re: [Repeater-Builder] Re: Is there a relationship between 147.225 and 146.925?
I sit corrected. Actually, I'm almost laying down corrected. I've never been so tired - even after Dayton. I had a really really busy weekend. I thoutoughly enjoyed it, but it was still busy. Anyway... I don't understand the intermod software's math that Ken happened to be using. :-) Joe M. Ken Arck wrote: At 07:45 PM 4/18/2004 -0400, you wrote: To be honest, I didn't follow Ken's math. Must be that west coast version. ;- Here is how I add it up: Aside from the formatting changes due to email, that's what my intermod software came up with. (sure sure, shoot the messenger!) 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: Is there a relationship between 147.225 and 146.925?
At 07:45 PM 4/18/2004 -0400, you wrote: To be honest, I didn't follow Ken's math. Must be that west coast version. ;- Here is how I add it up: Aside from the formatting changes due to email, that's what my intermod software came up with. (sure sure, shoot the messenger!) Ken -- President and CTO - Arcom Communications Makers of state-of-the-art repeater controllers and accessories. http://www.ah6le.net/arcom/index.html Be sure to see our products at this year's Dayton Hamvention! Repeater Builders spaces 707 through 710 AH6LE/R - IRLP Node 3000 http://www.irlp.net 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: Is there a relationship between 147.225 and 146.925?
Michael Singewald N1PLH wrote: First...Wow, you guys are FAST! I cannot believe how many responses in 15 minutes! Thank you all very much. The 147.225 has input 147.925 and the 146.925 has input 146.325. Actually, your input should be 147.825 for 147.225 out. To be honest, I didn't follow Ken's math. Must be that west coast version. ;- Here is how I add it up: 2A-1B: 147.225 + 147.225 - 146.925 = 147.525 146.925 + 146.925 - 147.225 = 146.625 (these are both OK unless you mix the results with the outputs, as each are 600 kHz off the TX of the other repeater) 3A-2B: 147.225 + 147.225 + 147.225 - 146.925 - 146.925 = 147.825 (sound familiar?) 146.925 + 146.925 + 146.925 - 147.225 - 147.225 = 146.325 (again, sound familiar?) Each of these cases results on the two TXs mixing and ending up with products on the inputs of the other. I don't understand the problem with the small difference in transmit frequency. The transmit frequency is still about 1 meg away from the receive frequency of the other repeater. How far apart in frequency would they ahve to be to co exist while running relatively low power? It's not how far apart they are - it's the math associated between them. The mixing products are killing you, not the signal strength. You can have a 5 MHz TX and a 440 MHz TX mix and end up with a product (3A-2B) on the 440 input, and those are 435 MHz apart! I don't know how the guy in Colorado put on 440 repeaters with WWV so close out there. Similarly, 600 kHz signals are bad for 2M repeaters, 1.6 MHz signals are bad for 220, just about everything is bad for 6M depending on where you live ;-, Etc. I don't think a different frequency will be possible since all seem to be taken. Another location is always a drag as well. It may be a drag, but may be the easiest solution. One case in my area had two repeaters that are about 20 miles apart had a very similar problem. I think the frequency outputs were 146.670 and 147.270 MHz. Again, 2B-1A was killing them. The solution on that case, I think, was to change to a BPBR duplexer rather than a notch duplexer. Joe M. 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: Is there a relationship between 147.225 and 146.925?
A=frequency 1 B=frequency 2 Formula for your frequency products is 2A+b, 2A-B, 2B+A, 2B-A. Simple math! -Original Message- From: mch [mailto:[EMAIL PROTECTED] Sent: Sunday, April 18, 2004 16:46 To: Repeater-Builder@yahoogroups.com Subject: Re: [Repeater-Builder] Re: Is there a relationship between 147.225 and 146.925? Michael Singewald N1PLH wrote: First...Wow, you guys are FAST! I cannot believe how many responses in 15 minutes! Thank you all very much. The 147.225 has input 147.925 and the 146.925 has input 146.325. Actually, your input should be 147.825 for 147.225 out. To be honest, I didn't follow Ken's math. Must be that west coast version. ;- Here is how I add it up: 2A-1B: 147.225 + 147.225 - 146.925 = 147.525 146.925 + 146.925 - 147.225 = 146.625 (these are both OK unless you mix the results with the outputs, as each are 600 kHz off the TX of the other repeater) 3A-2B: 147.225 + 147.225 + 147.225 - 146.925 - 146.925 = 147.825 (sound familiar?) 146.925 + 146.925 + 146.925 - 147.225 - 147.225 = 146.325 (again, sound familiar?) Each of these cases results on the two TXs mixing and ending up with products on the inputs of the other. I don't understand the problem with the small difference in transmit frequency. The transmit frequency is still about 1 meg away from the receive frequency of the other repeater. How far apart in frequency would they ahve to be to co exist while running relatively low power? It's not how far apart they are - it's the math associated between them. The mixing products are killing you, not the signal strength. You can have a 5 MHz TX and a 440 MHz TX mix and end up with a product (3A-2B) on the 440 input, and those are 435 MHz apart! I don't know how the guy in Colorado put on 440 repeaters with WWV so close out there. Similarly, 600 kHz signals are bad for 2M repeaters, 1.6 MHz signals are bad for 220, just about everything is bad for 6M depending on where you live ;-, Etc. I don't think a different frequency will be possible since all seem to be taken. Another location is always a drag as well. It may be a drag, but may be the easiest solution. One case in my area had two repeaters that are about 20 miles apart had a very similar problem. I think the frequency outputs were 146.670 and 147.270 MHz. Again, 2B-1A was killing them. The solution on that case, I think, was to change to a BPBR duplexer rather than a notch duplexer. Joe M. 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/
Re: [Repeater-Builder] Re: Is there a relationship between 147.225 and 146.925?
Michael Singewald N1PLH wrote: First...Wow, you guys are FAST! I cannot believe how many responses in 15 minutes! Thank you all very much. The 147.225 has input 147.925 and the 146.925 has input 146.325. (147.225 * 3) - (146.925 * 2) = 147.825 (146.925 * 3) - (147.225 * 2) = 146.325 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: Is there a relationship between 147.225 and 146.925?
Michael Singewald N1PLH wrote: I don't understand the problem with the small difference in transmit frequency. The transmit frequency is still about 1 meg away from the receive frequency of the other repeater. How far apart in frequency would they ahve to be to co exist while running relatively low power? Look at it this way, a UHF machine utilizes a 5 meg split. UHF repeaters still require a duplexer to operate without desense, or at least cavities if a 2 antenna system is utilized without enough vertical antenna separation. Since the 2 meter band is only 4 megs wide, you cannot separate the two repeaters in frequency enough to make it work without some additional equipment. I don't think a different frequency will be possible since all seem to be taken. Another location is always a drag as well. When you say equipment is available, are you referring to expensive multicoupler type sytems? That is one of the best solutions. Both repeaters could share the same antenna system and co-exist, but I don't think it would be possible with the current repeater pairs due to the nature of the frequencies. Even though they are on separate antennas? How far are they apart? I realize I could experiment with notches, but in your opinions (which I appreciate), that won't help enough? I've seen people spend thousands of dollars to solve problems with mathematical related issues, and they not be solved. It would be cheaper to move one of the repeaters to another frequency pair, and then solve any desense problems (due to transmitter noise) if they exist with notch filters, especially since neither of the two involved repeaters are really of commercial quality. 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/
Re: [Repeater-Builder] Re: Is there a relationship between 147.225 and 146.925?
Circulators will solve the problem if the mix is only occurring in the transmitters. They will not help if the mix is happening in a receiver front end or anywhere else, for example the proverbial rusty tower bolt. Circulators could add to your problem. They are infamous for producing harmonics. They should be followed with a bandpass cavity. The bandpass in your duplexer may not be sufficient to keep the harmonics down. Good luck! Jeff At 03:00 PM 4/18/2004, you wrote: If circulators would solve the problem, by all means they would be added. I read a little about them when all the discussion here about them was going on. I will have to go back and reread the info. --- In Repeater-Builder@yahoogroups.com, Ken Arck [EMAIL PROTECTED] wrote: At 11:46 AM 4/18/2004 -0700, you wrote: Not to mention there are all sorts of odd order mixes with his freqs: ---you guys considered adding circulators to your transmitters? That would solve the mixing issues.. Ken 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/
