21 March 2015
Well, the 2-meter remote is out, and a 220 MHz remote is going in. At some point in the future the 52.900 MHz repeater will be linked to the 224.120 MHz repeater in the Whittier Hills. This repeater, currently on the N6DHZ call, has historically been part of the SARS network and was linked in at Sierra Peak with the 447.100 MHz and 52.800 MHz systems there. The remote was out of service for several years and was removed during the reconstruction that occurred a couple of years ago.
Recently we discovered that a path exists between the Whittier site and the Yorba Linda site, and we thought it would be cool to link the two repeaters. Meanwhile we are still working out issues with the link to Sierra Peak. The Yorba Linda end of the circuit is complete, but the hilltop end is still "up in the air."
So that 220 remote is in my shop now, all tuned up and ready to go, except there's a problem with the power control circuit for the SAV-15 final PA. It works, but the power adjust circuit is generating a lot of heat, and I need to figure out why. Hopefully I'll have that up and running before too many more weeks go by.
I am looking for some MICOR CTCSS encoder reeds ... specifically 141.3 Hz.
If you have any, please drop me a line!
22 February 2015
I think I have figured out my problem with the CORs in the Daniels rack, but it may be a few days before I can prove or disprove my theory. It has to do with those forty-odd jumpers in the receiver modules and the way the S-Com 7330 works with COR inputs.
14 February 2015
The link antenna (a Larsen / Antenex Y4066 6-element yagi, 10.2 dB gain) is installed. Measured insertion loss of the antenna system at the transmitter frequency is -17.51 dBRL (VSWR 1:1.31). Not bad, given the age of the feedline (LDF4-50 with LMR-400 pigtails, at least ten years old, probably more) and the fact that there are two Nf-Nf barrels in it. Measured bandwidth of the antenna at the -15dBRL (VSWR 1:1.43) points is approximately 381 - 451 MHz.
I spent some time yesterday analyzing the jumper configurations of my receivers, the audio control card, the system monitor card, and the subrack backplane. I have a wealth of information to now pour over, hopefully I can turn up something to explain why the COR for each receiver goes active with a signal in any one receiver.
8 February 2015
The rack rail problem was eventually overcome, and after a false start Saturday 31 January, the link radio was installed today ... sort of.
The above image shows the Daniels SR-3 subrack loaded with modules for UHF TX and RX as well as VHF high band TX and RX. The UHF modules are for the link to the SARS network, the VHF modules will eventually be controllable via the S-Com 7330 as a multi-channel remote base. The UHF modules are connected to an antenna feed, the VHF antenna system has yet to be built.
I am having a problem with the Daniels radio (or the S-Com 7330, but I'm 90% convinced it's the Daniels equipment). When either receiver in the Daniels rack goes active, both CORs (UHF and VHF) go active. Those of you who know Daniels stuff know that there are a bunch of jumpers for various configurations in all these different modules. I went through them all to no avail. I will most likely be contacting the factory (now Codan Radio) soon to double-check my configuration and perhaps get some pointers.
The receive interface is complete. In fact, the only immediately pressing thing I have left to do with this equipment after de-bugging the COR issue is to adjust the TX audio to the UHF and VHF transmitters from the 7330 and mount the directional antenna for the UHF link system. Later I'll come back with the VHF high band antenna system and sus out the interface between the 7330 and the Daniels VHF transmitter / receiver.
So here's the cabinet as it looks 8 February 2015:
21 March 2015
An eight-bay DCI filter is being modified by Dan N6BKL for use with the 52.800 MHz repeater. At this time I do not know when the work will be complete, and I'm not going to pester him about it while he's doing me the favor of working on it for me. But when it is done it will do an excellent job of blocking all but a narrow, 1 MHz wide chunk of the six meter spectrum, and that window will be tuned for optimal performance on 52.300 / 52.800 MHz. It is my fond hope that this will put to rest the interference issue we have been having on the 52.800 MHz repeater.
If it does not, the next step in the plan is to mount an intermodulation panel. I have such a device, but (like everything else) it needs to be modified to suit our needs on 52.800. I believe the I, with a little bit of Dan's help and instruction, can get that done as well, should it prove to be necessary.
We are aware of the interference issue that is plaguing the six meter receiver. I'm not certain where it's coming from, but we have a construction project under way to install a narrow band-pass filter that will basically provide better than 60dB attenuation or more to anything falling outside a 1MHz window centered on 52.525 MHZ. It is my hope that once this filter is installed the N6FFI repeater should settle down nicely.
The audio on the link channel from Sierra to Oat is still low. We have not had a chance to get back to the mountain to correct this. Users on Sierra are difficult to hear on Oat (and hence Frazier). Audio coming back is fine, however. Rod and I are planning a site visit in February to correct that, and perhaps to tinker with the UHF repeater as well.
Aside from the occasional interference to its receiver, the 52.800 MHz N6FFI repeater is doing well.
Not much traction or forward progress on the "Kenwood Tray" repeater. I just haven't had the time to work with it ...
Stay tuned ...
Coverage map rendered by Bob Dengler NO6B
using "Radio Mobile Deluxe" software.
No coverage plot for the N6FFI repeater is available at this time.
E-mail the trustee.
Page last updated 31 January 2015