Many things to cover in this addition. First, the NEW 449.850 AllStar repeater is now on the SkyHubLink full time in Colorado Springs. Skyler WØSKY and I put it on the air from the “Gardner Rock” site on the southwest side of town up in the foothills. Thanks to our good friend Vic Michael for allowing us on the site and Dave West of Mountain Country radio for the internet connection. The repeater has GREAT coverage so far, up and over Monument Hill north of town and south to just north of Pueblo plus out onto the eastern plains. We have been searching for a Colorado Springs coverage repeater for quite some time and now are able to serve this area with a SkyHubLink connection. We decided to do this one analog to introduce more amateurs in the area to the SkyHubLink and ease of setup in this case. More on the new repeater later in the “Hamshack”!
With the thunderstorm and lightning season well underway one of the projects I wanted to accomplish was getting our node radios for the YSF system link that connects the Wires-X linked repeaters to the rest of the SkyHubLink. And, I decided to homebrew the 449.450 analog AllStar node radio antenna instead of using a vertical that I had employed. A simple 5 element Yagi plan made from some brass rod and loose molding that I had on hand in the garage junk bin. I wanted to mount the antenna inside the garage, and since I am line of site to the repeater at 11,440 feet, I really didn’t lose any signal that would have caused problems. Since the YSF link radio antenna is a professional level 3 element heavy duty beam antenna and is mounted in my attic on the other end of the house from the garage, a little separation between the antenna’s wouldn’t be a bad thing. In the pictures below you can see the easy construction and how simple the antenna is. Now there is about 30 feet separation and both antennas are “inside”, so I don’t have to disconnect them during storms, thus losing link node radio service to the repeaters.
The simple construction of the repeater Yagi, cut for the middle of the 5 MHz of the 449.450 repeater output and the input, so it is cut for 446.950. In the picture blow you can see the simple soldered feed point on the split driven element. Standard element spacing is used. And the mounting is keeping with the simplicity of the design. Mounted to the rafters in the garage and out of the elements, the antenna has been on the air now for about 2 weeks as of this writing and is working well connecting 449.450 to the SkyHubLink system.
The antenna mounted in the garage and the analyzer measurement using a NanoVNA
My good friend and SkyHubLink colleague Mark NØXRX worked this past month on a derelict Heathkit SB-200 amplifier that had really needed a restoration for quite some time. It had sat on a shelf for who knows how long and was quite in need of some loving care by a good technician. Mark really knows his stuff, so with that I will let him tell the story of getting this fine amplifier back in operational order.
The AMP definitely was owned by a smoker at some point in its life. It had a lot of smoke residue all over the case and frame. The front light came on when I powered it up, but the tubes wouldn’t. With some simple troubleshooting I found at least two capacitors in the power supply that were bad and a few other things.
I picked up a new power supply with some more modern components and a much cleaner package. Well I had to assemble it.
I replaced the RCA RF input with an upgraded SO-239
I found bad/broken diodes as well. The crystal diode was hard to find and I’m still waiting on it to arrive. The silicon diode I had in my parts bins.
I installed a slow-start relay board to protect the power supply and the tubes. This is a mod from Harbach Electronics. They only provide the parts and I assembled it. The trick was getting a good place to mount it (They don’t provide the mount).
I installed a slow-key as well so I can use it with modern radios like my ICOM IC-7300 and Yaesu FT-991 without the need of an external adapter box. This is also from Harbach Electronics. This was a tight install.
After cleaning everything up this is how it ended up.
Now tubes all work, well the best that I can tell so far. I still need the RF diode before I can start doing other tests.
I still need to install a protection circuit for the meter. Apparently, that is the hardest and most rare part to buy so I want to protect it. There are some other mods available, but I think I already have way too much time and money into it so far.
Mark Thomas – N0XRX
Thanks for the contribution to the “Hamshack” article Mark! GREAT JOB! It looks amazing!
The node radios at the home QTH were originally in separate racks on either side of my operating position and it was difficult to see the 449.450 link setup in the upper right-hand rack due to a computer monitor placement. With the new antenna setups and the way they fed into the shack where I wanted them finally it was easy to place the two node radio’s and power supplies where I can always see the fronts of the radio’s and the power supplies, plus makes much easier access for troubleshooting any possible issues that could crop up. This is a project I have wanted to complete for quite sometime so that there would be easier access to the UPS and the network connections.
BACK to Colorado Springs, here are the pictures of the day Skyler and I installed the 449.850 analog AllStar repeater. Skyler built the repeater out of a Raspberry Pi3, two Motorola radios, and the UREI interface box. The Pi serves as the repeater controller and AllStar network interface, with audio interfaced in the UREI.
The Motorola MaxTrax receiver, MCS2000 transmitter and power supply on the rack shelf
Skyler assembling the Diamond X-50 repeater antenna
Jack mounting the antenna on the standoff and THE
Last week on Lookout Mountain and the 449.625 Wires-X repeater there were several electrical power hits to the site that took out the hard drive on the computer that takes care of the Wires-X functions and links to the SkyHubLink Wires-X room 46361. Over the weekend I rebuilt the computer using Windows 8.1 instead of the old Windows 7 system, did the system updates, the remote Wires-X system configurations for unattended operation. By the way, be sure to do this on your Wires-X computers as you don’t want updates and other computer functions happening during main usage hours. You want to make sure that full restarts will take place if power anomalies happen. Now the system is back on air on Lookout Mountain updated and working perfectly. And dusted! Speaking of electrical power, see the system below that Jeff AK6OK has set up at his repeater site in Auburn CA covering Rocklin, Roseville, and the area NE of Sacramento CA.
A couple of years ago now I wrote about my 5BTV vertical tilt over mechanism that I built from a couple of pieces of angle iron and bolts with wing nuts. This has been a very beneficial and inexpensive way to have a much easier time repairing and maintaining my vertical antenna. I also had previously modified the antenna for 12 and 17 meters by adding wires fed at the bottom of the antenna and supported by PVC spreaders attached to the antenna after reading about them in another article. Well after a few years, the antenna needed some repair and attention as one of the “spider” elements between the 20- and 40-meter sections of the antenna had broken and fell. The wire antennas had fallen too with the top spreader support. With the addition of the mounting scheme you see below, repairs to full operation only took a little while with the addition of my tilt over homebrew mechanism. The two top wing nut bolts are the vertical supports, the bottom is the pivot point.
The tilt over mechanism that pivots on the bottom bolt next to the feed line in this view. The two red wires are the 17 and 12 meter ¼ wave wires.
The antenna tilted over for repairs. You can see the pivot point mounted to a pole in the ground on the right. Below is the mounting point for the “spider” element of the antenna.
The “Spider” element repaired, and the top spreader secured in place for the wire elements for 17 & 12 meters. Below another view with the suspension lines in place on the PVC spreader.
The repaired antenna back in its upright and locked configuration and new suspensions for the 17- and 12-meter wires.
Want to see a great article about an urban antenna installation, go to this website suggested by George NO7O from the Monday Night NET:
HAMSHACK ARCHIVES FILES
4 Years AGO: http://www.smpte-sbe48.org/wp/2016/07/
5 Years AGO: http://www.smpte-sbe48.org/wp/2015/07/
6 Years AGO: http://www.smpte-sbe48.org/wp/2014/07/
Click HERE TO CHECK OUT the latest BDR.net articles at: https://www.thebdr.net/articles/thisweek.html