LOOP_ANTENNA_FOR_35_MHz

Published:2009/7/8 23:22:00 Author:May | From:SeekIC

C1=3750 pF 500 V siver-mica capacitor．C2=100 pF preset capacitor(Jackson C803)C3=75 pF variable capacitor(Jackson C809)，plus knob．C4=12.7 pF variable capacitor(Jackson C16)，plus knob.C5=22 nF mica capacitor．M=250 μA f.s.d.40×40 mm moving coil meter(Maplin LB8O8)．D=HF silicon diode．R=1 kΩ resistor(see text)．L1=51/8 turns of PVC covered stranded 7/O.2 mm wlre，Outside diameter:1.2mm，1 kV/1.5 A rating(see text)L2=13 turns 16SWG tinned wlre，1 inch internal diameter．Feedline=48 inch RG58 coaxial cable，plus plug to suit transmitter．Box=ABS box type MB3，118×96×45 mm Maplin ref LH22．Terminal blocks=qty，412-way 2 amp terminal block Maplin ref，FE78．Spacers=qty.3 insulated spacer type M3，30 mm long，Mapin ref.FS4OT．Spokes=qty．48-foot lengths of 5/8×l/4inch molded hardwood(DIY store).Vertical support=23×O.8×0，Sinch wood(DIY store)．Wood base=12×8×0.5 inch plywood or simiar．21/2 inch steel support bracket． 1. 4 lengths molded hardwood 3O x 5/8 x 1/4 Varnished. 2BA holes drilled in the centre. Glued and bolted together.2. 8 off 6-way 2-amp polythene terminal blocks used as insulated wire spacers.3. 51/8 turns of PVC stranded wire (for specs see component, list).4. See Fig. 3.5. Wood vertical support 23 x0.8 x0.8 , wood stained.6. 2 x 2BA bolt.7. Box front vertical support, 41/2 x 1/2 x 3/4 , wood stained.8. Wood base 12 x 8 x1/2 (for similar), wood stained.9. 21/2 steel support bracket behind wood vertical support.10. Drilled and secured with glue and c/s wood screws.Note: = inch＝2.54cm. Suitable for receiving or transmitting (10 W or less) on the 80-m band, this loop antenna might be helpful when an outside antenna is not possible.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Basic_Circuit/LOOP_ANTENNA_FOR_35_MHz.html

Print this Page | Comments | Reading(3)