Dec 04 2013
Oct 29 2013
My exploration of available 33cm radios continues. I recently acquired a Motorola XPR6580 HT. This radio is capable of 800/900MHz and both digital (DMR/TDMA) as well as analog operation.
I currently have it programmed for local analog 33cm repeaters, however I’m exploring the options/opportunities to play with TRBO. Programming is not the easiest process. You have to program bogus channels with the programming software, then while that software is running, load in a hex editor and read that part of memory used by the software, search and replace, then save back the active memory. It’s a very tedious process. Additionally you must work from your saved file. Reading the radio will result in all non-standard channels being converted back to non-ham frequencies.
All in all, I’m rather pleased with the radio. It has great receive and seems to do well inside while working local repeaters. I may look at getting a UHF version in order to play with the TRBO options since there is an international network of 70cm TRBO repeaters.
Attached is a picture of my radio. If you have any questions, please feel free to let me know!
Oct 23 2013
I think I’m finally to the point of being able to say I’ve completed my first conversion of a 900MHz Maxtrac. The radio originally started out as a trunking multi-channel (talkgroup) radio. I replaced the trunking PROM with a conventional PROM and went through the process of blanking the radio and re-aligning it. Details on the process are available here.
The only part of the alignment I was unable to complete was the TX deviation as I had no way to inject audio with the programming cable (non-RIB) that I’m using. I’ve got a schematic and I think I can build a jig to allow me to inject the audio, so I’ll revisit that soon. I also have a few more of these radios to convert. I did not replace the filters as part of this operation. I do have some 915MHz ceramic filters that I was able to track down in the UK, but I’m trying to use those sparingly.
After I’d completed the re-alignment process, I ran the radio on my bench for a day or so and even made a couple of QSOs. Then I took it out to install it in a buddy’s car, and I had no receive. Brought it back to the bench and the problem was still here. On the suggestion of a fellow Ham, I cracked it open and checked the steering voltages for RX/TX. Sure enough, they were low. So I went though the process to bring up the voltages outlined here.
I buttoned the radio back up, including putting the cover back on the VCO, and the radio would neither transmit or receive. At this point, I opened it back up again and checked the steering voltage. It was 8.88VDC on either RX or TX, which is WAY to high. So I cracked up on the VCO again, and removed some of my silver circuit ink. I can only surmise that when I was heating the VCO case to replace the cover, some of the silver “ink” flowed a little bit and raised the voltages. I found that the steering line voltage is extremely sensitive to even the most minute amount of “ink.” After playing around with it a while, I was able to get the voltages in line for both RX and TX. So I reassembled the radio AGAIN, and so far so good.
Oct 15 2013
The club for which I serve as President has adopted a new name and a new call sign. Originally the club was named after a common employer, but was forced to change the name due to conflicts with the marketing department. Then after I left the employer back in April of 2013, it was decided that the club should not be associated with the former employer or any other employer.
So with that, The Naptown Amateur Group (Callsign N9AG) was born. Check out our website here: www.n9ag.org.
Oct 10 2013
Since returning from vacation, I’ve been busy trying to get the shack back in order and get my work area functional again. I picked up (and built) a new Kobalt Bench, and now have it in the shack. I’m still trying to figure out where or how I’m going to place my test equipment so that I can use/access all of it. Once I get things put together, I’ll post some pictures.
Sep 25 2013
The mobile installation worked great during our trip to Gatlinburg. I mostly worked PSK31 and JT65 while mobile. I’ll tell you that keeping a lengthy QSO going while traveling down the road can be tricky, but a lot of fun. I logged contacts throughout central Europe and a few state-side contacts as well.
Due to the location of our suite, my Antenna situation was extremely limited and exhibited poor performance. So the only real operating I was able to do was during the trip down and up.
All in all, I’ll call my first venture into mobile HF a success and a lot of fun. I’m going to work on figuring out a more permanent antenna mount and getting rid of the mag-mount I’m using now. I also need to install a couple more NMO mounts to support he APRS radio, etc.
Aug 28 2013
Here are a few pics of my 2008 Jeep Liberty. It is now equipped with HF in the form of an Icom IC-706MKII. I’ve installed a laptop for logging and digital modes. I actually made a JT65 contact from my driveway tonight.
As work progresses and I tidy things up, I’ll post more pics. If you have any questions or would like more detailed pics, feel free to ask!
Aug 23 2013
I figured I’d post an update regarding some of the activities that are going on in and around the shack.
First off, the SVXLink project has stalled out while I search for a radio interface. After finally getting it to compile on the Raspberry Pi, I was able to configure it up and get it to connect to Echolink and was able to log in via my iPhone/iPad. The system will not, however, key up the repeater. The interface board I’m using, the AMI-2, doesn’t use the same pins for COR that SVXlink is looking for. So I may have to build an interface for it. I’m still looking forward to getting it up and running so that I can put the WIndows laptop away and get something running more stable.
The repeater projects are still moving along:
- 33cm: I received a suggested 33cm frequency pair from the IRC, but unfortunately the input is being used by another local group, so I’ve given that information back to the coordinator and I’m awaiting an updated pair suggestion. I do have a 16dB pre-amp and a 150W final amplifier. I’ve also received the 915MHz filters in, so I’ll be replacing those in one of my TK-981′s that will be used as the receiver. K3HTK and I still need to do the modifications on the external amps, but the pieces continue to fall into place. Thanks to K9YDO for the loan of a 24VDC power supply to drive the amps.
- 70cm: I picked up two Micro 75W amplifiers at the Lafayette Ham Fest. I’m hoping to bench and fire them up this weekend. 500mW should give me ~75W out. Since the new 70cm repeater is centered around UHF Maxtrac’s I’m likely going to need to do a low power mod to stabilize the radio. This involves a 10k pot and three resistors to regulate the voltage going to the VCO. I have also submitted the update to my coordination to the IRC for the increased power level. I will likely seek out a UHF pre-amp as well to round out the project.
In other news, I’ve jumped back into APRS. I’ve had an Alinco DR-135T for a number of years. It’s just been sitting in the shack. I picked up a $40 GPS puck from Amazon and have it interfaces with the radio. I’d initially planned to just setup the unit as a tracker as phase one and then expand my capabilities with phase two. However, as tends to happen with projects in this hobby, phase one and two are rapidly merging into a single phase. I have a laptop mount and pole left over from my previous police car, and I’ve ordered the foot plate to mount that in my 2008 Jeep. Right now I’m using APRSISCE/32 on a Windows 8 laptop, and plan to mount that in the Jeep. That same laptop will also be used for digital HF work once I get the IC-706MKII installed (see next note).
I’ve decided to take my first steps into a mobile HF operation. I’ve purchased an Icom IC-706MKII from a fellow ham and have pieced together the remote mount kit for it. I also have the LDG-Z100 tuner with the appropriate interface cables to allow it to function remotely from the control head. I’m currently working out mounting options for what will be the fourth radio in my Jeep. Planning to take the radio on vacation so I’ll have APRS running as well as digital HF (when I’m not driving). The mobile antenna dilemma is still working itself out. Short-term I’ve purchased a tri-mag mount for the top of the car and am going to try out a single 20M Hamstick off of one of my dipoles. I plan throw that on the roof this weekend and see how it tunes up with one of my analyzers. Long term will likely lead toward some sort of screwdriver antenna.
The best thing about this hobby is that there is always something new to try…. So many projects and so little time…..
Aug 07 2013
Last night I decided to use my most recently acquired Raspberry Pi as a replacement for the windows laptop running the echolink software linking the NF9k and K3HTK repeaters.
Unfortunately since the RasPi is based upon the ARM processor, there are no readily available binaries for the Pidora/RasPi platform. So I downloaded the tarball and sat out on the path of compiling it for myself. It took me the better part of about three hours to track down all of the dependencies that popped up early in the make process. I went to bed with it happily compiling.
When I got up this morning, I discovered that the build had broken on another dependency. So it was lather, rinse, repeat. After tracking down three or four more dependancies, I am happy to report that I have successfully built and installed SvxLink on my RasPi!
Tonight I plan to install a Senheiser USB sound card as well as the AMI Echolink USB board and see what happens. If all goes well, we might be able to begin testing this evening….. Fingers crossed!
Aug 01 2013
The rack has moved from the garage to the shack. The Arcom, Cat 200 (currently unused), and the TKR-820 have been racked. Not sure on the final in-rack arrangement yet, but its a step in the right direction. The laptops pictured, one is the programming laptop for the Arcom and the other is for Echolink.