I needed a simple cable to program two Motorola GM360 radios using a ribless cable. A search on the internet revealed a diagram. It uses a cable that connects directly to the computer without needing any special box. It is important to note that ribless cables are only suitable for programming CPS code plugs to the radio and not for flashing the radio with new firmware. For flashing the radio with new firmware, you would need a RIB.
Here is my version of the cable. Well I found that your cable length must be as short as possible. Also ensure that your cable connections fits well to the radio and the PC. I 3D printed a cabinet for the USB – TTL adapter. Simple two hour project.
This is the 2m / 70cm Half-Wave antenna using white 25mm electrical conduit - to build a dual bander antenna.
The
basic half wave version of the Flower Pot antenna can be readily
modified to dual band the antenna for operation on a band that is the
(approximate) third harmonic of the fundamental resonance.
Operation on the third harmonic is achieved by using a sleeve
technique so as to form quarter wave phasing sections (at the higher
frequency) to end feed two half waves in phase at the third harmonic.
This arrangement provides useful gain (3dBd) on the higher band.
The sleeve technique maintains the impedance matching for both bands
and (probably fortunately) there is sufficient longitudinal impedance
in the choke coil to provide the required isolation at the third
harmonic.
I decided to build this antenna as part of the New Series - Building Low Budget Antennas. Here is my version of the above antenna:
General Specifications:
Resonant Frequency: 145.250 Mhz
Frequency Span: 144.200 - 145.800 Mhz
Modes: FM ( Local
repeaters and simplex)
Polarity: Vertical (Note: Repeaters use vertical
polarization.)
Antenna Impedance: 50 Ohm or very close to 50 Ohm
Gain: Some gain but could not find any scientific proof
I found a very useful Flower Pot Antenna Calculator if you want to change the measurements to suite your needs. This calculator is used to determine the length of each element of
the flower pot antenna. That includes the
upper radiator, lower radiator, also the length of the cable that
will be wound on the PVC pipe.
Enough said let's start building the Half-Wave Flower Pot Antenna.
Materials I used:
2.5 meter of 50 ohm RG58CU Mil Spec coax
1 x PL259 Connector (Not ideal rather use BNC or N-Type Connectors but I used what I had on hand)
1 x 1.5 meter 25mm Electrical Conduit pipe
1 x 25 mm PVC End Cap (The Co-Op is your friend here)
1 x 50mm length of 6.5 mm heat shrink tubing to fit over the coax cable
1 x 50mm length of 5mm heat shrink tubing to fit over the inner coax cable
1 x 100mm of fishing line
1 x plastic sucker sweat stick (Blue in photo)
1 x brass chocolate block connector to hold top radiator upright.
1 x 462.8 mm x 2 mm solid insulated copper wire for the Top Radiator Element. ( I use this instead of the normal fine stranded inner wire of the coax.)
Odds and Sods:
Cable Ties
Hot Glue Sticks
Insulation Tape Solder Solder Paste 5 -10 m Coax Cable (RG58CU Mil Spec) 50 ohm with 2 x Connectors (Feeding line to radio) Self Amalgamating Electrical Tape PVC Cement ("Glue") (Permanent gluing of the PVC caps.)
Tools:
Metal Punch Drill Drill Bits 6 mm + 3mm Hack Saw or PVC Pipe Cutter Hot Glue Gun Soldering Iron Sharp Utility Knife Screw Driver (Small flat)
Test Equipment:
VHF SWR Meter Antenna Analyzer (If you have one but not compulsory) VHF/UHF Radio Coax Patch Leads Mast (Non conductive) Power Supply or Battery for Radio
Building the Antenna:
I am not going to go into detail how I constructed my version of the antenna as there is more than enough info on the Internet how to construct the antenna. Herewith a few links:
Who cares what this antenna is called. The proof is whether this antenna works as I am sure you would agree that this is a simple cheap antenna to construct. I and many others can confirm that this antenna work as described. It has many uses and variants that you can construct.
Testing the Antenna:
I ran a quick test on the antenna with my HT just to see what the SWR was like. Well the images speak for themself. SWR was low over a very broad spectrum (144.300 - 145.800 Mhz). In my case this antenna works better than one of my Diamond X50
antennas. But in all fairness I think the Diamond antenna might have a
problem. With the Flower Pot antenna about 1 m above the roof I can work
the 145.750 Mhz Aasvoelkop Repeater with 2 watts which I cannot do with the Diamond
X50 which is about 3m above the tiled roof. I could also trigger all the local repeaters in the George / Mossel Bay area with two watt output. I will do some more tests once I invest in a VNA Antenna Analyzer. More on this in a future posting.
Side Notes:
I found that the antenna works just as well on 70cm without the aluminum sleeve. SWR 1.2:1 on 70cm. Not having a VNA and high power dual band radio to do further test I presume that the low power of the HT's keep the SWR at bay. I need to do further tests in this regard.
Conclusion:
This antenna will be great for HOTA, SOTA, POTA and even Emergency Communications. It is lightweight and easy to setup/install. To the new radio amateurs this antenna is an ideal first time antenna project. Give it a try and forward your build images to me for posting on this Blog.
The following site was recently activated by Corne ZS1COR. Several
other radio amateurs were also present in support of the days
activities. The images underneath reflect the history and activation of
the site which was registered on H.O.T.A.
Image: Fancourt
History of Fancourt
The history of Fancourt, its families and people, begins in 1860. British engineer, Henry Fancourt White, settled with this wife, son and daughter at the foot of the Outeniqua Mountains near George. Here, he built an elegant family home, known as Blanco House. It was designed in the style of an old Cotswold mansion.
Henry White played a vital role in the development of the commercial infrastructure around the area’s Montagu Pass. Shortly after his passing, the property was auctioned and sold to his son, Ernest Montagu White. He renamed the house “Fancourt” in honour of his father and made extensive restorations. Montagu passed away in a tragic incident of wild mushroom poisoning, which saw the property fall into a state of disrepair.
In 1960, after almost 30 years of neglect, Dr. Roland Anthony Krynauw, a South African brain surgeon, purchased the property. He began to restore it to its former glory. Today, the refined Manor House is a national monument and a testament to his dedication.
In 1989 the estate passed hands again and was transformed into a top-class hotel and golfing destination under the direction of Andre and Helene Pieterse.
Today, the extensive Fancourt estate is owned by Dr Hasso and Sabine Plattner. Fancourt offers a luxurious, contemporary and relaxed environment, perfectly blending the charms of its family origins and rich heritage with modern convenience. With award-winning golf courses, fine dining, wellness and family-friendly facilities, all Fancourt guests, from the youngest to the oldest, are assured that they will feel at home.
More information visit the website of Fancourt by clicking HERE
Images: (Click on images for larger view.)
Corne would like to thank all those who contacted the station and
also who assisted him during the activation.
What is HOTA?
H.O.T.A (Heritage on
the air) is an amateur radio group that strives to motivate radio
amateurs to learn more about history, and to keep history alive by
activating a multitude of historical sites by using SSB, AM, FM, CW
and even with Heliographs. Radio amateurs have great fun going out
in the field and visiting places and areas where once history was
made. Even if you do not like history there is places that were
visited that might be of interest to you. You can even combine your
other hobbies with H.O.T.A. Now that you have a faint idea of
H.O.T.A it is time to learn more about H.O.T.A and the fun radio
amateurs have and can have in activating historical sites.
If you want to learn
more about H.O.T.A you can visit the Heritage on the Air website by
clicking HERE.
So 'n tyd gelede het ek en Christie ZS4CGR 'n gesprek gehad rondom die uiters wisselvallige Internet diens wat hy op die plaas van tyd tot tyd ervaar het tydens veral beurtkrag maar ook sommer in die algemeen. Hy het my meegedeel dat die boere en hyself in die omgewing waar hy woonagtig is sommer vir dae sonder Internet en selfoondienste is. Hy is by een van die groot Internet verskaffers die enigste een wat hy is sy area ontvang. Van landlyn dienste is daar nie eers 'n teken nie. Soos ons almal weet maak 'n boer 'n plan wanneer hy 'n probleem ervaar wat opgelos moet word. So is daar ook ander dele in die land wat nie normale Internet verbindings het nie, maar ook geen verbindings tydens beurtkrag nie. Ons het ook reeds ervaar dat amateur radio nadelig beinvloed word wanneer beurtkrag toegepas word en ek gaan nie nou hieroor uitbrei nie aangesien ek dit reeds vele male verduidelik het in die verlede.
Ek was die afgelope tyd besig om te kyk na alternatiewe kommunikasie vir die GRHub Netwerk wanneer Internet of selfoon kommunikasie in duie stort tydens beurtkrag. Ek hoor talle se maar gebruik amateur radio toerusting. Dit is onveilbaar. Ja ek kan dit gebruik maar ek wou sekere kommunikasie middels en sagteware gebruik en nie net RF radio nie. Meer hieroor in 'n toekomstige plasing. Kom ons kyk wat het die afgelope weke met Ok Christie gebeur.
Ek ontvang die volgende selfverduidelikende Winlink epos vanaf Christie op die 13 Oktober 2023. Nee nie op my Winlink stelsel nie, maar via my gewone gmail epos adres.
Noem dit 'n "nood oproep" vanaf die plaas want kyk ons as radio amateurs gee om vir mekaar as ons nie gereeld van mekaar hoor nie. Ek kon toe die lede van die Amateur Radio 101 groep inlig hoekom ons nie van Christie iets hoor nie.
Ek het besluit om in antwoord op die epos vir Christie 'n Winlink Epos terug aan hom te stuur via sy winlink epos adres. Ek het die epos met PAT Winlink wat op 'n Raspberry Pi geinstalleer was gestuur asook 'n beeld afdruk (image) van sy oorspronklike epos. Wel op 15 Oktober 2023 is die PAT Winlink epos afgestuur insluitende die aanhangsel. Ek het die epos ook ge- "CC" na my gmail epos toe. Sonder enige probleme is die epos aan OK Christie gestuur. Winlink werk en dit werk goed ook wanneer daar geen Internet koppeling is nie.
En so kan mens in verbinding bly met radio amateurs op plekke waar daar nie Internet of selfoon ontvangs is nie. Speel bietjie rond met Winlink. Dit is beslis die moeite werd om dit deel te maak van jou arsenaal van sagteware en hardeware.
Here is another simple project. No I did not create the 3D printer file for this cabinet. I was looking for a small cabinet to house a USB / Ethernet Converter. I decided to modify an original project box by scaling it down to size for the converter. At the sea it is not a good thing to leave PCB's out in the open and unprotected even in the Shack.
What will this USB /Ethernet Converter be used for? My AllStar / Echolink Node has only one ethernet port. I need another port to connect the GRHub Network to the AREDN Network. This works great and the ZS1I AllStar /Echolink GRHub Network is now connected to the ZS1I AREDN Network. Services on the GRHub Network and AREDN Network is now visa versa available to radio amateurs using one of the networks. This means that apart from 2m RF, AllStar / Echolink, RF Links all voice and data is now relayed also on 2.4 Ghz and 5.8 Ghz. The biggest benefit of this is that when there is an Internet outage locally the GRHub Network (AllStar, Repeaters and Links) are still working via the two networks with no Internet connection. Echolink however does not work when there is a Internet outage. This way I can keep VHF/UHF/HF amateur radio communications going. More on this in a future posting.
