[Repeater-Builder] Re: New to 900mhz,, PL or DPL?
Then it's not COR [Carrier Operated Relay]. It would be RUS [Receiver UnSquelch]. And running any voice station strictly on PL/DPL is a bad idea. PL [CTCSS] is prone to falsing if it isn't AND'ed with carrier detect. I have to figure that DPL is better, but random energy from the 'hiss' has got to false the decoder once in a while. BTW, my agency uses the same 2 PL tones across the state, whether high RF site or not. And the majority of 440 ham repeaters in my area use the SAME 100.0 Hz tone for access. So, unless you have some desire to restrict who can access your repeater [since some radios WON'T do DPL], then my recommendation is PL. But stay away from 179.9 Hz, as that can be falsed by the third harmonic of the mains. And choose one that's neither at the top nor bottom of the list. WalterH --- In Repeater-Builder@yahoogroups.com, kq7dx kq...@... wrote: Thank you for all the replies and great information. I have another question on code selection. Other than 411 being a code used for open repeater, what is the criteria for picking a DPL code. Also it looks like PL being preferred to DPL is not RFI specific as I have seen on frequency lists with PL being used in high RFI locatations. What do you think about leaving the squelch open and letting the DPL control the COR. Thanks again... The DPL list I found. Standard 83 Digital Coded Squelch Codes 0nn 1nn 2nn 3nn 4nn 5nn 6nn 7nn 023 114 205 306 411 503 606 703 025 115 223 311 412 506 612 712 026 116 226 315 413 516 624 723 031 125 243 331 423 532 627 731 032 131 244 343 431 546 631 732 043 132 245 345 432 565 632 734 047 134 251 351 445 654 743 051 143 261 364 464 662 754 054 152 263 365 465 664 065 155 265 371 466 071 156 271 072 162 073 165 074 172 174
[Repeater-Builder] Re: New to 900mhz,, PL or DPL?
Thank you for all the replies and great information. I have another question on code selection. Other than 411 being a code used for open repeater, what is the criteria for picking a DPL code. Also it looks like PL being preferred to DPL is not RFI specific as I have seen on frequency lists with PL being used in high RFI locatations. What do you think about leaving the squelch open and letting the DPL control the COR. Thanks again... The DPL list I found. Standard 83 Digital Coded Squelch Codes 0nn 1nn 2nn 3nn 4nn 5nn 6nn 7nn 023 114 205 306 411 503 606 703 025 115 223 311 412 506 612 712 026 116 226 315 413 516 624 723 031 125 243 331 423 532 627 731 032 131 244 343 431 546 631 732 043 132 245 345 432 565 632 734 047 134 251 351 445 654 743 051 143 261 364 464 662 754 054 152 263 365 465 664 065 155 265 371 466 071 156 271 072 162 073 165 074 172 174
[Repeater-Builder] Re: New to 900mhz,, PL or DPL?
I think this comes down to personal preference. I know a lot of folks who will argue that one or the other is better but they both do what they are supposed to do. Some say there are a lot of falsing issues with PL and that DPL doesn't false. In actual use, I have heard both false. Some say there are interference problems with certain tones. This can be true in some situations. DPL will give you more choices since there are more DPL codes than PL tones. As far as I know, any modern radio designed originally for 900 MHz commercial use will do either well. I personally prefer PL because there are more after market devices for that format and it is easier to implement in some situations such as with phase modulated exciters. But it is still just my personal preference. Your Maxtrac should handle either format. --- In Repeater-Builder@yahoogroups.com, kq7dx kq...@... wrote: Hello to the group, I have had a couple of really nice hams try to explain this to me but I am not getting it. Which is better. Most importantly which is better in a metropolitan city with lots of RFI and noise on the bands. Particularly 900mhz. I have seen mostly PL and just a few DPL listings so I am not sure that it is RFI motivated for the selection. So which is best for a repeater application. The receiver for the repeater will be a 800mhz Maxtrac converted to 902mhz. Thank you for your help, and if this was covered on another post please let me know. I am on a dial up and it is hard to research. 73s scott
Re: [Repeater-Builder] Re: New to 900mhz,, PL or DPL?
One caution - The 900MHz Motorola GTX series radios have a firmware bug in them and will NOT do tone reverse burst at all. The DCS side of the radio is just fine. This is documented on the GTX pages at repeater-builder. Since every 900MHz user radio that is in use started out as a commercial 2-way they all have both PL and DPL, so the choice of PL tone or DPL code and the choice of which tone or which code is up to the person who sets up the system. Since the GTX is a popular an entry-level radio you will find a LOT of repeaters use DPL, and for what it's worth in some areas DPL code 411 is considered an open code - i.e. if the system uses 411 then it's an open system. As to tone selection criteria, the CTCSS overview article (which also contains some historical info) at repeater-builder has some very cogent points - like you DON'T want to use 136.5 Hz or 131.8 Hz on any channel that you might want to run DPL on in the future. See http://www.repeater-builder.com/tech-info/ctcss/ctcss-overview.html There is also a chart of legal DPL codes at the end. Too many systems are out there that use nonstandard codes. Mike WA6ILQ At 06:35 AM 02/25/10, you wrote: I think this comes down to personal preference. I know a lot of folks who will argue that one or the other is better but they both do what they are supposed to do. Some say there are a lot of falsing issues with PL and that DPL doesn't false. In actual use, I have heard both false. Some say there are interference problems with certain tones. This can be true in some situations. DPL will give you more choices since there are more DPL codes than PL tones. As far as I know, any modern radio designed originally for 900 MHz commercial use will do either well. I personally prefer PL because there are more after market devices for that format and it is easier to implement in some situations such as with phase modulated exciters. But it is still just my personal preference. Your Maxtrac should handle either format. --- In Repeater-Builder@yahoogroups.com, kq7dx kq...@... wrote: Hello to the group, I have had a couple of really nice hams try to explain this to me but I am not getting it. Which is better. Most importantly which is better in a metropolitan city with lots of RFI and noise on the bands. Particularly 900mhz. I have seen mostly PL and just a few DPL listings so I am not sure that it is RFI motivated for the selection. So which is best for a repeater application. The receiver for the repeater will be a 800mhz Maxtrac converted to 902mhz. Thank you for your help, and if this was covered on another post please let me know. I am on a dial up and it is hard to research. 73s scott Yahoo! Groups Links
[Repeater-Builder] Re: New to 900mhz,, PL or DPL?
Here in southern New England where the 900MHz band has flourished in the absence of a 70cm network. I have not been personally involved in putting any of the repeaters on the air, but I can tell you that the split is pretty even between Pl/DPL. Not sure how it will work with a 800 to 900MHz conversion most of the gear used around here in intended for 900MHz use (mostly Motorola equipment). Best advice I can give you is www.gemoto.com they are the driving force behind our 33cm movement and have lots of technical knowledge. 73, Jeremy KB1REQ --- In Repeater-Builder@yahoogroups.com, kq7dx kq...@... wrote: Hello to the group, I have had a couple of really nice hams try to explain this to me but I am not getting it. Which is better. Most importantly which is better in a metropolitan city with lots of RFI and noise on the bands. Particularly 900mhz. I have seen mostly PL and just a few DPL listings so I am not sure that it is RFI motivated for the selection. So which is best for a repeater application. The receiver for the repeater will be a 800mhz Maxtrac converted to 902mhz. Thank you for your help, and if this was covered on another post please let me know. I am on a dial up and it is hard to research. 73s scott
