Circular Polarization - Turnstile Antenna for 80 meter band
with JUMA Turnstile Controller JUMA TC
2018-07-12 OH7SV


Click the pictures to enlarge


Turnstile antenna on map


Turnstile antenna dimensions (only on dipole drawn)



Turnstile antenna setup in the field. Mast 15 m. Guy wires 1mm and 2mm
Kevlar ropes.


Art image in fog by XYL Ulla


Turnstile antenna GND view. 18 meter Spiderbeam shortened to 15 meters.


Fiberglass mast bottom. Note the two coax cables, one for each dipole.
Low loss Ultraflex7 (wimo.de) one
electrical wave length cables, each 67.3 meters.


Installation team OH7SV, OH7FVG, OH3YP and OH2NLT photographer.
Installation was during the JUMA 10 years celebration at OH7SV remote station.


Antenna material


Dual common mode balun. Back plate is 6 mm Polycarbonate.
The box is Multicomp
G256 Polycarbonate 80 x 80 x 55 mm.


Two common mode baluns in the box. 7 turns RG-316 PTFE coax on Wurth 742700790
ferrite core.
The polycarbonate plate is fixed to fiberglass mast with stainless steel 28mm U-bolts.


2 x type N water proof bulkhead sockets. Note the breathing holes on the bottom of the box.
All screws, washers and nuts are stainless steel material A4.


JUMA TC Turnstile Controller. It can be used from QRP level to legal power.
You can select between remote control and X, Y, LHCP, RHCP antenna.
It is compatible with Remoterig I/O by interface with standard ethernet cable.
You can remotely select
X, Y, LHCP, RHCP antenna with the two I/O signals. See Remoterig snap-hot.
PTT control signal is needed to swap polarization between transmit and receive state.


JUMA TC Turnstile Controller main board layout.
The dummy load is implemented with two 35W SMD resistors.


Close view of the quadrature hybrid coil for 3.7MHz. 13 turns 1mm enamel cu wire in parallel.
Core
iron powder Amidon T-106-6. Other bands are possible with corresponding windings and capacitors.
The coil reactance XL is 2 x 50 ohms and both the capacitor's XC is 100 ohms each for desired frequency.

JUMA TC Turnstile Controller Schematics (pdf)

JUMA TC Turnstile Controller Layout (pdf)


JUMA TC Turnstile Controller BOM (xls)

Many thanks to Michael OH2AUE for helpful advice!

  JUMA TC (Turnstile Controller) is available as a kit with a price of 115€ from JUMA SHOP
To EU countries the price is 142.60€ (VAT 24%)


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