RE: Re: [dstar_digital] Re: Inside Chassis coax - lossy
They appear to be custom rigs. Housed in an aluminum enclosure (the same as the ID-1, less the powder coating) I have photographs of the RP4000V, RP2D, RP2V, RP2C. The same basic configuration is used. No TX components in the Rx Units. Custom boards for the application, though all quite similar. Doesn’t look at all like my ID-800, or my friends 2820. They appear to be like modified ID-1s, even the UHF unit. Perhaps after field day I can put some of these images up on the net. -Greg Zenger, N2GZ From: dstar_digital@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Ron Wright Sent: Saturday, June 28, 2008 10:58 AM To: dstar_digital@yahoogroups.com Subject: Re: Re: [dstar_digital] Re: Inside Chassis coax - lossy Nate, and all, Nate we knew you were coming from a hecked day. You usually don't go this way and know you've used mobile duplexers. The cabling is, as you said, the problem. Do you or anyone know what rigs ICOM uses in the repeater. Looks like a pair of mobiles put in a box, big box. Wonder what mobiles. Appears they have been modified for rcv and xmt (fan removed on I think the receiver heat sink). I understand there is a different controller/CPU that puts out data and rigs are controlled with raw data with no rcvr DStar demod. I wonder what are the specs of these rigs. I bet they are one of the mod'd ICOM mobiles. 73, ron, n9ee/r Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome. [Non-text portions of this message have been removed]
Re: Re: [dstar_digital] Re: Inside Chassis coax - lossy
Mobile duplexers work very well. Repeaters have been built for years with the mobile duplexers inside the repeater enclosure with very good performance. If replacing the cables and moving outside I would think the cables were the problem and not where the duplexer was. Since you replaced the cables this is probably the solution and not the moving the duplexer outside. This tells me the repeater had poor cables to start with. 73, ron, n9ee/r From: Nate Duehr [EMAIL PROTECTED] Date: 2008/06/27 Fri AM 01:59:59 EDT To: dstar_digital@yahoogroups.com Subject: Re: [dstar_digital] Re: Inside Chassis coax - lossy On Jun 26, 2008, at 1:15 PM, Mike wrote: Also the UK 70cms module came with a ready pre-tuned duplexer that was mounted inside the case, as soon as we moved it outside of the case and fed it direct with decent coax the difference was unbelievable in sensitivity.
Re: RE: [dstar_digital] Re: Inside Chassis coax - lossy
This loss is about .11 db/ft, little more than RG58. If one used RG223 (double shielded RG58) the loss would be about the same. Going to RG214 loss would be .05 db/ft, an improvement. All this is at 400 MHz. At 400 MHz the .11db loss would be .63 watts from 25 watts. I don't think much improvement would be realized if replaced. Also not sure all the other specs of the cable; double shielded, silver solder, etc? This would also be factors I would consider. I do like the idea of removing the cable and replacing a single cable from each rig long enough to get to the duplexer, but to simply replace the 10 cable with another would not be of much concern as loss goes. If desense problem then this is another issue. 73, ron, n9ee/r
