Post by Paul OM0ET (Admin) on May 11, 2019 21:40:36 GMT
This 4th version of the QRP UltraLight MLA antenna has the same foldable construction designed for easy carry in a common laptop bag same as the 3rd version. This antenna was designed primarily for 40m to 12m bands + CB. Diameter of the main loop growed to 1m and same hight as the ver.3. I have used a wider PVC tubing of foldable boom. All this changes caused higher efficiency on all bands, especially on 40M band which was missing in the 3th version of UltraLight MLA. By using this same variable capacitor I was not able to reach the 10M band. Capacitor is connected in serial fashion because of very low resistance in a whole antenna circuit what is very important to secure a high Q and high efficiency of my loops. I decided to do made 4th ver. because of longlasting poor propagations on higher bands due to a deep Solar minimum in the present years.
The tuning box is made of the solid plastic. For SWR measuring I have used the QRP transceiver XIEGU X5105. The SWR on all bands is better than. 1:1.5
This v. 4 MLA is working from 7MHz to 27,8MHz continuously and CB band is covered too.
Total weight is only +/- 960 grams. No switch is needed. It's a QRP version for 5 to 20W (max. 10W CW / 20W SSB).
Please do not exceed the power limit of 20W! It may cause a fire on the capacitor plates or demage PA in your transceiver.
Dimensions:
Large loop diameter: approx. 1m ( wire lenght is 3141 mm / 10,304ft )
Small loop diameter: approx. 29cm ( wire lenght is 932 mm / 36,69inch )
Capacitor: air type with ELTRA 2x 243pF with small gearbox reduction - used in split stator mode
Large loop is made of Nordix MWC 10/50 microwave coaxial cable (can be used RG213U but it's not hold the shape of ring as Nordix)
Small loop is made of 3,5mm copper wire PVC isolated
The boom is made of 3 pieces 467mm long and 25mm in diameter PVC pipe
Total weight: +/- 960g
Fishing tripod adapter:
I have made this new fishing tripods adapter. Is suitable for any standard fishing tripods. With this adapter is very easy to mount entire antenna on the tripod.
If you have some questions write down below please
The tuning box is made of the solid plastic. For SWR measuring I have used the QRP transceiver XIEGU X5105. The SWR on all bands is better than. 1:1.5
This v. 4 MLA is working from 7MHz to 27,8MHz continuously and CB band is covered too.
Total weight is only +/- 960 grams. No switch is needed. It's a QRP version for 5 to 20W (max. 10W CW / 20W SSB).
Please do not exceed the power limit of 20W! It may cause a fire on the capacitor plates or demage PA in your transceiver.
Dimensions:
Large loop diameter: approx. 1m ( wire lenght is 3141 mm / 10,304ft )
Small loop diameter: approx. 29cm ( wire lenght is 932 mm / 36,69inch )
Capacitor: air type with ELTRA 2x 243pF with small gearbox reduction - used in split stator mode
Large loop is made of Nordix MWC 10/50 microwave coaxial cable (can be used RG213U but it's not hold the shape of ring as Nordix)
Small loop is made of 3,5mm copper wire PVC isolated
The boom is made of 3 pieces 467mm long and 25mm in diameter PVC pipe
Total weight: +/- 960g
Fishing tripod adapter:
I have made this new fishing tripods adapter. Is suitable for any standard fishing tripods. With this adapter is very easy to mount entire antenna on the tripod.
If you have some questions write down below please