Some great news this weekend! The LP-500 is bought and paid for, as is the Flex 6500 and the Comet CHA-250B. I was also notified by the Flex Service Dept. that my 6700 is ready. The FlexRadio units will arrive together on Friday, and hopefully the LP-500 arrives around the same time. All hardware in transit!
These are the last few items to complete the station. Once installed, the radio rack will be moved back into the operating position, and the shack furniture will be put back into place.
I’m a week away from wrapping up all the new hardware! Hardware in transit is a good thing!
The Comet CHA-250BX was delivered a few days ago. Today I assembled it and mounted it on a ‘test stand’ in the back yard, next to the W6LVP Loop. Tomorrow I will run some LMR-400 coax down there and we’ll see how the 6500 plays on this antenna. Right now the 6500 is connected to a non-resonant dipole antenna, so here’s to hoping the vertical does a much better job.
Before I can run the coax I have to replace the cover on the window in the shack. The current window covering is a piece of heavy duty art board of some kind. This art board material was never intended for use that would expose it to the elements. It is weathered and it’s shape is distorted, so it must be replaced. I plan to install a piece of Optix Acrylic to cover the open space above the air conditioner. I have a L-R sliding window so I’ve had to cover this open space ever since getting the air conditioner. Once this is complete I’ll have a better pass-through for all the cables. I also hope to pull in some of the rotor cable slack off the roof, into the shack, so I can reconnect the satellite rotors.
My ‘test stand’ is the bottom part of an old umbrella stand. It seems to hold up OK but I’ll probably add a couple of sand bags.
Everything they said about it is true!
The CHA-250BX performs exactly as claimed. I replaced the window and ran the coax today [SAT 12/22] and the 6500’s internal tuner tunes this antenna fairly flat on all bands! 1.3:1 was the highest reading I observed today. I’ll post more exact results later on.
This antenna will be used primarily as an RX antenna for SSTV/Digital modes. Low power, 100 watts max TX, “bare foot” no amplifier. I managed to tune through a few bands this afternoon and so far it looks like a winner.
Just what I needed in a wideband antenna!
Santa Claus will be a day late with the LP-500 (it’s arriving WED). The LP-500 is the final component of the 2018 hardware upgrade. I joined the LP-500 waiting list in May 2018 at number 200 something, these days, the list is much shorter as they catch up to demand.
Once the installation of the LP-500 is complete, I’ll be looking forward to “buttoning everything up” with the radio gear and reinstalling the shack furniture.
I’ll use the Geochron to learn how to work, and better understand, the “Grey Line“. I hope to develop some new DX’ing skills in the process. Working Grey Line DX will be a new thing for me to look forward to.
On another note…
I was unable to pull in any significant amount of the slack in the satellite rotor cables. It will require a roof climb. My HF rotor also needs it’s control cable replaced (after 14 years in the SoCal sun) So these will be done at the same time, but no time soon. It’s time to get operating.
The Comet CHA-250BX vertical has been on the test stand long enough. It’s time to move it into a permanent location on the property.
I plan to put the CHA-250BX on the top of one of the support masts that currently hold up one end of my “Height Compromised Dipole“. It’s in the corner behind a palm. I read a few eHam reviews that mentioned good results were achieved by mounting the CHA-250BX just 10 to 15ft above the ground. The antenna height affects the take-off angle, and apparently 10-15 feet is yielding some good results. I’m already working some DX barefoot via FT8, so I know the antenna performs OK. With all the testing, I now have a baseline to compare the performance against once it’s at the new height.
New Location For The CHA-250BX
If you look closely at the image below you can see the mast in the corner of the yard. I had it strapped to a huge stake that I drove into the ground. It was held in place using hose clamps. It stood up straight for years until part of the palm died and knocked it loose. I’m going to extend the current 100ft Andrew CNT-400 with another 50ft of the same coax.
Recycle The Base Parts
The test stand is an old umbrella stand. I plan to fit the weighted base squarely into the corner against the cinder block wall, and secure it using the big stake, and the 50 lb sandbag.
This steel mast is 15ft tall, a 5 ft section on top of a 10 ft section. When I re-deploy the mast I will switch the 5 ft section to the bottom, this way, when I have the antenna ready to go I can stand on a step ladder and insert the 10 ft section much easier. If 15 feet is judged to be too tall to stabilize, I will eliminate the 5 foot section.
Square In The Corner
The umbrella stand will fit perfectly into this corner.
I have some mollies leftover from a recent flower trellis repair. I can use some of them as anchors for the steel straps if it looks like I’ll need them..
Comet CHA-250BX At Ideal Height
The 5 ft section will be reinforced using two sets of steel straps (at 1 and 5 feet above ground), and an additional guy line to reduce or eliminate any sway. I’ll add a pulley to the top for the dipole, and hang a weight from the end insulator to reduce stress on the mast when it’s windy. I’m also going to devise a wooden support beam that will go in between the mast and the 90 degree concrete corner. I’ll be able to tighten the steel straps to keep the mast firmly against the beam. I’ll square one end of the wooden beam for the corner, and make a cutout for the mast diameter on the other end. This should be a rock solid base. The antenna is 23.8 feet tall, and weighs 7 lbs. with a 67 mph wind rating.
I have a spare ground rod which I will install at the base.
Update: Sat 05/18/19
XYL: Where Did You Put That Antenna?
Tucked away nicely in the corner of the yard! Barely noticeable to the XYL.
There are several articles out there about antenna height versus take-off angle. There seemed to be some consensus that a height of 3 meters above ground offered some improvement in performance.
I decided the antenna would not be stable at the proposed height. Its proximity to neighbors property is also a factor. So instead of 15 feet, I mounted it at 10ft (3m)
OK. Let’s see what kind of results we get. The antenna had to move anyway, so hopefully we get some good results.
I leave two instances of WSJT-X FT8 running 24/7. Then, when I get home from work, I scroll back through the RX windows to see what was heard while I was away. I’ve been running it this way since I first put up the CHA-250 vertical back in March 2019.
I’d left it on 40m since yesterday afternoon (just over 24 hours) and came home today to find EU callsigns in the FT8 console for the first time. Lots of DX calls, among them Italy, Croatia, Morocco, Mauritius, Ecuador, Japan, Indonesia, Philippines, New Zealand and on and on. Keep in mind this is just the past day on 40m! I never saw anything like this when the antenna was on the test stand.
If you have your CHA-250BX mounted on the ground give it a try on a 10ft mast! Let’s see how many of these newly heard DX callsigns can be worked!
the bonus: antenna separation
An added bonus! The increased antenna separation between the vertical and the RX Loop has eliminated the de-sense I was seeing on the 6700’s HF RX. As I work FT8 I am usually listening to 80m on the 6700/W6LVP Loop. The antenna separation is now sufficient that the FT8 transmissions no longer interfere with other HF RX in the shack. Perfect world.
it Turns out to be a major upgrade!
EA3KU 05/21/2019 05:15 FT8 100w 40M Sent -11 Rcvd -20
F6AOJ 05/25/19 04:28 FT8 100w 40M Sent -17 Rcvd -22
EA8TH 05/2519 06:23 FT8 100w 40M Sent -19 Rcvd -22
WSJT-X was installed on 03/09/19 and my DX contacts up to this point included JA’s and ZL’s and VK’s, but I hadn’t copied any EU callsigns before raising the antenna. Now I’m working into EU, so I am very pleased with this upgrade.
update 03/09/20 wsjt-x results
At this point, I’ve worked thousands of FT8 QSO’s and some great new DX. All you need is a 100 watt radio and this inexpensive antenna in order to work the world!