Updated on 12/14/2015 at the bottom.
Original post 9/2/2014:
In my area D-STAR/D-RATS is used for emergency communications traffic handling. Since I first discovered this I have been baffled by it. Because of widespread and highly reliable land-line and cellular telecommunications systems and broadband internet amateur radio is looked upon as being increasingly unessential as a communications tool. Amateur radio correctly responds to this by stating that while these systems are highly reliable they are subject to failure via natural disasters, computer failures, or direct terrorist attacks on theses systems. While an individual amateur station may be rendered inoperable because of any of these same events it is virtually impossible that all amateur stations even in a small region surrounding an event would be unable to operate. Thus amateur radio is a reliable, proven, and necessary emergency communications fallback that will continue to be needed for the foreseeable future.
Why then would Emergency Communications organizations such as ARES choose a tool such as D-STAR that is 100% dependent on the internet? If the internet goes down, D-STAR goes down, period. It is possible that it could still be used for message traffic between stations in direct communication with each other, I'm not sure. But to link directly to the county or state EOC and send traffic, forget it. If I don't have a D-STAR radio and I rely on D-RATS then I completely lose the system if I lose the internet. Another downfall to D-STAR that is too obvious to need addressing is that D-STAR is only available to owners of expensive Icom D-STAR compatible radios.
I'll grant that D-STAR isn't a completely horrible option and having not used it I'm sure it has merits that make it highly desirable. I'll also grant that it is fairly unlikely that an entire region will lose the D-STAR network. My guess is this is why its faults (internet reliance and being restricted to one radio brand) are overlooked. As mentioned above I still find that its inherent reliability on the internet precludes its use an an ECOM tool. For the individual station it is an even worse choice. While it may be unlikely for the D-STAR system to go down over a large area for any particular event I find it quite likely that the internet will go down at an individual station or repeater located in an event area. If my station relies on either D-STAR via local repeater or D-RATS via the internet and my area loses the internet then I have lost my ability to communicate as trained. The whole ECOM system, or at least the part handling traffic out of the event area, must now change its message handling method wasting valuable time in the process.
Why would ECOM managers choose a tool that is going to fail?
Why also when there are other options out there? The Hybrid WL2K system uses the internet when the internet is available but automatically switches to an HF only system on loss of the internet. This system provides nationwide coverage and can be accessed by HF via Winmor, Pactor, or Packet and by VHF/UHF via Packet. For most stations already using digital HF modes all it takes is another piece of software and a very short learning curve. WL2K is only one example and I'm sure there are other options.
My goal in posting this is to influence those that may agree to speak to your local and state ECOM managers in hopes that a more reliable system is adopted before we have a system failure when the system is needed the most.
Update 12/14/2015: Recently I learned that D-RATS can be used over the air with a TNC connected to an analog (non-D-STAR) radio. In this configuration I think D-STAR/D-RATS would be an excellent tool since it does not rely on the internet, assuming all critical users are using this configuration and are not relying on the internet.
Tuesday, September 2, 2014
Tuesday, March 4, 2014
New Equipment, 630m, and Updates
It's been a while since my last post and since then there have been several changes to my shack and project updates.
Back in September my mic headset failed during a HF net, basically I had no speech. I replaced it with another multimedia type electret model. Several weeks later I discovered that I had bad RFI on 40m while transmitting, it occurred even while tuning. The most recent change to my shack was the addition of the new headset. I unplugged the headset and was able to tune with no problem. It seems that the cable for the new headset was picking up my transmissions on 40m and feeding that back to the mic. I wrapped the cable through a type 43 toroidal ferrite, problem solved.
In December I got my hands on a Timewave PK-232SC. This is an upgraded version of the PK-232MBX TNC with an internal sound card. Now both TNC and sound card digital modes are through one box instead of two, simplifying my station and some of the connections to my rig and PC. Soon I'll start looking for a new home for my RIGblaster Advantage and AEA PK-232MBX.
Also in December I added a Yaesu FT-817ND to my shack. I bought it used as I have for most of my equipment and it came with a variety of accessories. I haven't done much with it yet other than to hook it up and verify it worked properly. At a minimum I need to get a tuner for it, probably a LDG Z-817. It came with W4RT OBF (one board filters) not installed. At some point I'll get those installed and add DSP. I'm working on speech compression/processing for it also. W4RT sells a speech compression kit that is added to the mic but I don't want to be restricted to just using the hand mic. There used to be an inexpensive module that plugged in between the the mic and the radio but that is no longer made. There are several similar designs I've found on the internet and I intend to try to build one soon.
One of the included accessories with the FT-817 was a set of Peg Leg tilt stands. Despite warnings not to use too much force installing the legs I managed to strip one the screws installing them. The company that makes the stand was nice enough to offer to send me a slightly larger screw to fix the issue when I contacted them for help.
In January I finally got a hold of an IF SDR/DRM panadapter made to go into one of the filter slots on my FT-897. It will also work with the FT-817 or FT-857. I've only used it a little but so far it's not quite what I thought it would be. My understanding is that it doesn't have some of the front end filtering that other panadapters have, maybe I can add that at some point. Because of the lack of filtering I can hear signals many kHz away from where I'm tuned, regardless of what filters I've selected in the software. There is also a watery sounding background noise that I hear post processing through my computer that I've yet to find and eliminate.
WSPR is one of the digital modes I enjoy from time to time. At my old QTH I tried in vain several times to receive WSPR signals on 2200m and 630m with no success. In January I tried again and found I could receive several 630m WSPR stations quite well. That kicked off 6 weeks of interest and research into obtaining an experimental license and the equipment and antenna needed to get on the air on 630m. At last, just recently, I've decided that for the time being I'm not going to pursue this any further. Once I looked at the effort and financial expense required (which can vary depending on your current setup and how much you want to home-brew your own equipment) and then compared that to other ham projects I decided it wasn't the most important project I wanted to work on. I did learn a lot in the process and maybe one day I'll revive the idea, maybe also it will become one of our regular bands at that point.
With that in mind my current projects are to get a full emergency power setup for my shack and to get the Raspberry Pi I got for Christmas setup as my portable digital mode computer to go along with my FT-817. I also still need to get my VHF/UHF antennas up, a progressing project.
Back in September my mic headset failed during a HF net, basically I had no speech. I replaced it with another multimedia type electret model. Several weeks later I discovered that I had bad RFI on 40m while transmitting, it occurred even while tuning. The most recent change to my shack was the addition of the new headset. I unplugged the headset and was able to tune with no problem. It seems that the cable for the new headset was picking up my transmissions on 40m and feeding that back to the mic. I wrapped the cable through a type 43 toroidal ferrite, problem solved.
In December I got my hands on a Timewave PK-232SC. This is an upgraded version of the PK-232MBX TNC with an internal sound card. Now both TNC and sound card digital modes are through one box instead of two, simplifying my station and some of the connections to my rig and PC. Soon I'll start looking for a new home for my RIGblaster Advantage and AEA PK-232MBX.
Also in December I added a Yaesu FT-817ND to my shack. I bought it used as I have for most of my equipment and it came with a variety of accessories. I haven't done much with it yet other than to hook it up and verify it worked properly. At a minimum I need to get a tuner for it, probably a LDG Z-817. It came with W4RT OBF (one board filters) not installed. At some point I'll get those installed and add DSP. I'm working on speech compression/processing for it also. W4RT sells a speech compression kit that is added to the mic but I don't want to be restricted to just using the hand mic. There used to be an inexpensive module that plugged in between the the mic and the radio but that is no longer made. There are several similar designs I've found on the internet and I intend to try to build one soon.
One of the included accessories with the FT-817 was a set of Peg Leg tilt stands. Despite warnings not to use too much force installing the legs I managed to strip one the screws installing them. The company that makes the stand was nice enough to offer to send me a slightly larger screw to fix the issue when I contacted them for help.
In January I finally got a hold of an IF SDR/DRM panadapter made to go into one of the filter slots on my FT-897. It will also work with the FT-817 or FT-857. I've only used it a little but so far it's not quite what I thought it would be. My understanding is that it doesn't have some of the front end filtering that other panadapters have, maybe I can add that at some point. Because of the lack of filtering I can hear signals many kHz away from where I'm tuned, regardless of what filters I've selected in the software. There is also a watery sounding background noise that I hear post processing through my computer that I've yet to find and eliminate.
WSPR is one of the digital modes I enjoy from time to time. At my old QTH I tried in vain several times to receive WSPR signals on 2200m and 630m with no success. In January I tried again and found I could receive several 630m WSPR stations quite well. That kicked off 6 weeks of interest and research into obtaining an experimental license and the equipment and antenna needed to get on the air on 630m. At last, just recently, I've decided that for the time being I'm not going to pursue this any further. Once I looked at the effort and financial expense required (which can vary depending on your current setup and how much you want to home-brew your own equipment) and then compared that to other ham projects I decided it wasn't the most important project I wanted to work on. I did learn a lot in the process and maybe one day I'll revive the idea, maybe also it will become one of our regular bands at that point.
With that in mind my current projects are to get a full emergency power setup for my shack and to get the Raspberry Pi I got for Christmas setup as my portable digital mode computer to go along with my FT-817. I also still need to get my VHF/UHF antennas up, a progressing project.
Monday, August 12, 2013
Random Wire Converted to OCF Dipole
The random wire antenna I put up at my new QTH has been less than ideal, good, but with some issues. I guess this was to be expected given the nature of the antenna and the fact that I didn't install a counterpoise or radial system. What further compromised the antenna is the fact that my shack is on the second floor. On certain bands, 15 meters especially, RF in the shack was causing issues. Specifically anytime I would transmit at any power level above about 5W my computer would lose connection with USB devices such as my external sound card and my CAT connection to my radio. There was another instance where my tuner would never quit its tuning cycle, it would continue to tune until I turned the radio off.
I'll post a summary sometime of what all bands I used on, but mostly it worked well enough. In search of some options to solve the RF in the shack problem I came across some info about off center fed (OCF) dipoles. I had heard of them before, and their predecessor the Windom, but I'd never given them much attention. To back up a little my antenna goals are two fold: 1)to have a multiband antenna and 2)that it work well on 80 meters for NVIS use. The plan was to eventually add an 80 meter dipole right above the random wire feed point to ensure a good solid 80 meter NVIS signal. Had I known that the OCF dipole was a multiband antenna I would have most likely put one up from the start.
The important part about an OCF dipole is where to feed it. Upon researching the antenna I came across an article by L. B. Cebik. The article describes two OCF dipoles, one at a fundamental frequency of 3.5 MHz and one at 1.75 MHz. Cebik goes to to describe how each antenna works and what the SWR curves look like when fed at different points. As it turned out my 220' random wire was the perfect length to the foot for one leg of a 275' 1.75 MHz OCF dipole fed at the 20% point. All I needed to do was add 55' wire off the other side for the other leg. The 20% point corresponds to a 200 ohm feed point impedance which requires a 4:1 balun to match with 50 ohm coax feed line, something I already had been using with the random wire. Converting my random wire to an OCF dipole was a simple as disconnecting the side of the balun that I had grounded and connecting a 55' wire to get to 275' overall length. It took a few hours to get it all done, including cutting a few limbs off of a tree for the far end of the 55' leg, and then i was on the air.
I modeled the antenna in the demo version of EZNEC and it compares fairly well to what my antenna analyzer shows. Initial results have shown a signal report that bests my random wire on 80 meters and no issues on any other band. So far, so good. As long as I don't run into any issues this will probably be my primary antenna for a while. I'll post more about how it is doing once I've had some more time on the air with it.
I'll post a summary sometime of what all bands I used on, but mostly it worked well enough. In search of some options to solve the RF in the shack problem I came across some info about off center fed (OCF) dipoles. I had heard of them before, and their predecessor the Windom, but I'd never given them much attention. To back up a little my antenna goals are two fold: 1)to have a multiband antenna and 2)that it work well on 80 meters for NVIS use. The plan was to eventually add an 80 meter dipole right above the random wire feed point to ensure a good solid 80 meter NVIS signal. Had I known that the OCF dipole was a multiband antenna I would have most likely put one up from the start.
The important part about an OCF dipole is where to feed it. Upon researching the antenna I came across an article by L. B. Cebik. The article describes two OCF dipoles, one at a fundamental frequency of 3.5 MHz and one at 1.75 MHz. Cebik goes to to describe how each antenna works and what the SWR curves look like when fed at different points. As it turned out my 220' random wire was the perfect length to the foot for one leg of a 275' 1.75 MHz OCF dipole fed at the 20% point. All I needed to do was add 55' wire off the other side for the other leg. The 20% point corresponds to a 200 ohm feed point impedance which requires a 4:1 balun to match with 50 ohm coax feed line, something I already had been using with the random wire. Converting my random wire to an OCF dipole was a simple as disconnecting the side of the balun that I had grounded and connecting a 55' wire to get to 275' overall length. It took a few hours to get it all done, including cutting a few limbs off of a tree for the far end of the 55' leg, and then i was on the air.
I modeled the antenna in the demo version of EZNEC and it compares fairly well to what my antenna analyzer shows. Initial results have shown a signal report that bests my random wire on 80 meters and no issues on any other band. So far, so good. As long as I don't run into any issues this will probably be my primary antenna for a while. I'll post more about how it is doing once I've had some more time on the air with it.
Thursday, July 11, 2013
The Counterpoise
A very misused term in amateur radio it seems. For instance when I was researching how to put up my random wire antenna I came across a recommendation to use a "counterpoise" of equal length to the random wire but attached to the shield side of the coax feed line and placed below the main antenna. This actually just makes the antenna a dipole (more or less) but with each leg parallel and close together and of "random" length. Another common misuse is to call the "tiger tail" that many add to HT antennas a "counterpoise."
I didn't know any better until recently when I decided to better understand what it was and was not. I'll let the reader discover it's real meaning and most common misuses in the following articles:
Counterpoise? (by L. B. Cebik, W4RNL)
Counterpoise (VK1OD on the 'net)
I didn't know any better until recently when I decided to better understand what it was and was not. I'll let the reader discover it's real meaning and most common misuses in the following articles:
Counterpoise? (by L. B. Cebik, W4RNL)
Counterpoise (VK1OD on the 'net)
Tuesday, June 25, 2013
Random Wire Is Up!
Or really, it has been up since May 25th. It was a 15 hour job all day on the 25th and that was after several hours of pre-installation work for a few evenings preceding the 25th. Because of ladder height and placement limitations I didn't get the mast quite where I wanted it. I think that will actually work out better in the long run but for this job it meant some longer and more difficult coax runs and changing my grounding scheme.
There is a lot of information on the web that describes ideal lengths for random wires, making them not random at all. These ideal lengths avoid half wave multiples on all the bands of interest. Some of these "ideal" lengths give you only a few feet of wiggle room in order to fall between half wave multiples. It is never mentioned how sensitive these designs are. We never operate at the exact same frequencies over and over again, so what happens when I'm "close" to one of these multiples? My guess is that a window on the order of a few feet is not enough in the real world.
My antenna is something greater than 200' but less than 230' (I think). I haven't used it on all bands but my AT-897 tunes it up from 1.8-50 MHz and all of the MARS frequencies that I have tried. That is exactly what I wanted it to do, whatever it's electrical length is. It is made from 14 AWG coated stranded wire fed about 20' off the ground via a COMTEK 4:1 current balun. The wire then runs to the ENE (60 degrees) for at least 150' coming to within 12' or so of the ground before hitting an insulator 20'+ up a magnolia tree. At that point it takes a hard left turn (a little greater than 90 degrees) and runs somewhere in the neighborhood of 75' sloping downward where it is terminated to an insulator on an oak tree about 12' off the ground. So I have a 200'+ "L" shaped sloping random wire, or something like that.
There was a lot of different information regarding feeding, grounding, and using counterpoises for random wires. Pretty much every resource had different information. Some resources suggested 1:1 current baluns, or 4:1, or even 9:1 or 16:1. Some 1:1 voltage baluns, some ununs of all ratios and some nothing at all. Some recommend a counterpoise or a radial network (with 1/4 wave radials on all bands of interest), others grounding the shield side (but not to the station ground), and again others nothing at all. The information in general agreed but there was no consensus: some sort of good ground or "other half of the antenna" was needed for efficiency I believe, usually some impedance matching was necessary or at least desired, and depending on the installation measures may have to be taken to keep RF out of the shack. Radials or a counterpoise was not going to happen, at least not at this time and not where I have the antenna and mast. Also, that and my shack being on the second floor caused me to have concerns of having RF in the shack. To prevent the RF in the shack issue I chose a 4:1 current balun with the shield side connected directly to a dedicated ground rod (OK, it is shared with the mast) via 6 AWG soild copper wire. If I understand correctly I'm basically directly grounding all unbalanced feed line currents. Not the best for efficiency but it keeps the coax feed line from radiating which keeps RF out of the shack. I almost went with a 1:1 balun and I'm glad that I didn't because I'm close to my tuner's impedance limit on some bands even with the 4:1 balun.
The mast is the Radio Shack coated galvanized type that I had left over from the old QTH VHF/UHF antennas. The only thing I don't like about it is that I have to sand off the coating to expose bare metal for ground connections, something that will have to be a periodic practice to remove the rust that will form and spoil the low impedance ground connection. I used some left over LMR-400 with crimp on/solder connectors as the feed line, this time with a drip loop at the balun. The DX Engineering entrance box is my common entrance point and station RF ground, grounded via 2" wide copper strap to its own ground rod. It is mounted on the outside wall of my shack on the second floor. The coax enters the shack via a coax lightning suppressor mounted on the inside of the box. On the inside wall of the shack I made an inner entrance panel out of a blank 3 gang box cover with 4 SO-239 bulkhead connectors and a ground bus. The ground bus is connected to to outside panel via 1" braided copper strap. My rig is connected to the inner panel via RG-8X coax with a common mode choke. The radio and tuner are grounded to the ground bus via 1/2" braided copper strap.
My next post will summarize my assessment of this antenna's performance. No fancy analysis, which I'm incapable of, just my observations.
There is a lot of information on the web that describes ideal lengths for random wires, making them not random at all. These ideal lengths avoid half wave multiples on all the bands of interest. Some of these "ideal" lengths give you only a few feet of wiggle room in order to fall between half wave multiples. It is never mentioned how sensitive these designs are. We never operate at the exact same frequencies over and over again, so what happens when I'm "close" to one of these multiples? My guess is that a window on the order of a few feet is not enough in the real world.
My antenna is something greater than 200' but less than 230' (I think). I haven't used it on all bands but my AT-897 tunes it up from 1.8-50 MHz and all of the MARS frequencies that I have tried. That is exactly what I wanted it to do, whatever it's electrical length is. It is made from 14 AWG coated stranded wire fed about 20' off the ground via a COMTEK 4:1 current balun. The wire then runs to the ENE (60 degrees) for at least 150' coming to within 12' or so of the ground before hitting an insulator 20'+ up a magnolia tree. At that point it takes a hard left turn (a little greater than 90 degrees) and runs somewhere in the neighborhood of 75' sloping downward where it is terminated to an insulator on an oak tree about 12' off the ground. So I have a 200'+ "L" shaped sloping random wire, or something like that.
There was a lot of different information regarding feeding, grounding, and using counterpoises for random wires. Pretty much every resource had different information. Some resources suggested 1:1 current baluns, or 4:1, or even 9:1 or 16:1. Some 1:1 voltage baluns, some ununs of all ratios and some nothing at all. Some recommend a counterpoise or a radial network (with 1/4 wave radials on all bands of interest), others grounding the shield side (but not to the station ground), and again others nothing at all. The information in general agreed but there was no consensus: some sort of good ground or "other half of the antenna" was needed for efficiency I believe, usually some impedance matching was necessary or at least desired, and depending on the installation measures may have to be taken to keep RF out of the shack. Radials or a counterpoise was not going to happen, at least not at this time and not where I have the antenna and mast. Also, that and my shack being on the second floor caused me to have concerns of having RF in the shack. To prevent the RF in the shack issue I chose a 4:1 current balun with the shield side connected directly to a dedicated ground rod (OK, it is shared with the mast) via 6 AWG soild copper wire. If I understand correctly I'm basically directly grounding all unbalanced feed line currents. Not the best for efficiency but it keeps the coax feed line from radiating which keeps RF out of the shack. I almost went with a 1:1 balun and I'm glad that I didn't because I'm close to my tuner's impedance limit on some bands even with the 4:1 balun.
The mast is the Radio Shack coated galvanized type that I had left over from the old QTH VHF/UHF antennas. The only thing I don't like about it is that I have to sand off the coating to expose bare metal for ground connections, something that will have to be a periodic practice to remove the rust that will form and spoil the low impedance ground connection. I used some left over LMR-400 with crimp on/solder connectors as the feed line, this time with a drip loop at the balun. The DX Engineering entrance box is my common entrance point and station RF ground, grounded via 2" wide copper strap to its own ground rod. It is mounted on the outside wall of my shack on the second floor. The coax enters the shack via a coax lightning suppressor mounted on the inside of the box. On the inside wall of the shack I made an inner entrance panel out of a blank 3 gang box cover with 4 SO-239 bulkhead connectors and a ground bus. The ground bus is connected to to outside panel via 1" braided copper strap. My rig is connected to the inner panel via RG-8X coax with a common mode choke. The radio and tuner are grounded to the ground bus via 1/2" braided copper strap.
My next post will summarize my assessment of this antenna's performance. No fancy analysis, which I'm incapable of, just my observations.
Monday, June 3, 2013
The Gulf Of Mexico Will Be The Place To Watch This Week
From Crown Weather:
http://www.crownweather.com/?page_id=7327
"The Gulf Of Mexico Will Be The Place To Watch This Week As Invest 91-L Possibly Develops Into A Tropical Depression Or Tropical Storm; Heavy Rain Of Up To 10 Inches Expected This Week Across South Florida"
http://www.crownweather.com/?page_id=7327
"The Gulf Of Mexico Will Be The Place To Watch This Week As Invest 91-L Possibly Develops Into A Tropical Depression Or Tropical Storm; Heavy Rain Of Up To 10 Inches Expected This Week Across South Florida"
Wednesday, May 22, 2013
Antenna plans have changed...
Antenna plans have changed at the new house...
When I started to look at the best route for a full wave loop I noticed that it was going to be pretty difficult to route the wire the way I wanted to (which would have involved getting on a high, steep roof and maybe climbing several trees). With that I decided to try a random wire. It'll run about 20 feet off the ground and will be "L" shaped horizontally with the main leg about 140-150' and the short leg 50-60' with the total length targeted to avoid 1/2 wave multiples of all bands from 10-80 meters. As is best practice with wire antennas I'll start with more wire and trim as needed. It would be a lot of trouble and somewhat undesirable to install a counterpoise and/or radial system and/or a tuner located right at the feed point outside the shack. Instead I'm going to use a 4:1 current balun (fed with a few feet of coax from the tuner in the shack) right at the feed point with the other side grounded to a dedicated ground rod. I know that is not an ideal installation but I'm going to give it a try.
My old setup on VHF/UHF, as previously mentioned, was a ground plane mounted above a 4 element Yagi with the Yagi direction fixed. At the new house I want the Yagi to rotate as I'm too far from most of the local repeaters to hit them on an omnidirectional antenna. Both antennas are currently mounted on a 10 foot section of Radio Shack TV antenna mast. The plan was to just sit that on top of a rotator and away we go. As I looked at that more two problems became evident: one is that two antennas and 10 feet of mast is too much to sit on top of a cheap rotator; the second is that in order to get the Yagi clear of my roof line the whole works is going to have to be a lot higher than I originally planned. I don't have an immediate need to get these antennas up so for the time being I'm going to focus on getting on the air on HF before getting back to this. I may have to let the Yagi sit behind part of the roof in order to avoid having to guy the mast. I did discover that there is a thrust bearing made to work for the rotator I'm going to get that will allow for better support of taller loads above the rotator. Using the thrust bearing will allow me to run the main mast from the ground parallel to the rotator mast for some length, taking the lateral load off of the rotator and transferring it to the main mast and house.
Once I get the rotator up I'll have a better setup to run a full wave loop in the future. In the meantime I may have to supplement the random wire with a dipole if I'm not getting the performance from the random wire that I desire.
When I started to look at the best route for a full wave loop I noticed that it was going to be pretty difficult to route the wire the way I wanted to (which would have involved getting on a high, steep roof and maybe climbing several trees). With that I decided to try a random wire. It'll run about 20 feet off the ground and will be "L" shaped horizontally with the main leg about 140-150' and the short leg 50-60' with the total length targeted to avoid 1/2 wave multiples of all bands from 10-80 meters. As is best practice with wire antennas I'll start with more wire and trim as needed. It would be a lot of trouble and somewhat undesirable to install a counterpoise and/or radial system and/or a tuner located right at the feed point outside the shack. Instead I'm going to use a 4:1 current balun (fed with a few feet of coax from the tuner in the shack) right at the feed point with the other side grounded to a dedicated ground rod. I know that is not an ideal installation but I'm going to give it a try.
My old setup on VHF/UHF, as previously mentioned, was a ground plane mounted above a 4 element Yagi with the Yagi direction fixed. At the new house I want the Yagi to rotate as I'm too far from most of the local repeaters to hit them on an omnidirectional antenna. Both antennas are currently mounted on a 10 foot section of Radio Shack TV antenna mast. The plan was to just sit that on top of a rotator and away we go. As I looked at that more two problems became evident: one is that two antennas and 10 feet of mast is too much to sit on top of a cheap rotator; the second is that in order to get the Yagi clear of my roof line the whole works is going to have to be a lot higher than I originally planned. I don't have an immediate need to get these antennas up so for the time being I'm going to focus on getting on the air on HF before getting back to this. I may have to let the Yagi sit behind part of the roof in order to avoid having to guy the mast. I did discover that there is a thrust bearing made to work for the rotator I'm going to get that will allow for better support of taller loads above the rotator. Using the thrust bearing will allow me to run the main mast from the ground parallel to the rotator mast for some length, taking the lateral load off of the rotator and transferring it to the main mast and house.
Once I get the rotator up I'll have a better setup to run a full wave loop in the future. In the meantime I may have to supplement the random wire with a dipole if I'm not getting the performance from the random wire that I desire.
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