About me SM4GGC
Antennas
Building 11 el 2m YU7EF EF0211B
Building 24 el 70 cm YU7EF EF7024
Old antennas
EME slide show
QTC EME 23cm

About me SM4GGC
Born in 1953 and has worked with mobile communications and telecommunications since 1973. I was interested in ham radio early when I was 14-15 years old together with my younger brother SM6FGN. My brother learned CW rely fast so he did get his license for ham radio at 16 years age but I struggled some more years with CW before I could pass the test for ham radio.
In the mean time was I building radio equipment transmitters, receivers and antennas that my brother could operate from our parents house. First years was it for HF but just when I was ready to pass my license for ham radio did I discover VHF 2 M and the thrill to make long distance QSO via tropo and aurora
When I got licensed 1973 was the plan to build a station at my parent’s summer house located at JO69XB with good take off and free horizon over lake Varnern perfect for VHF. At this time was there no electricity at the house so a gasoline generator was the solution. Antennas for 2 M was growing from 2x13 el, 4x12 el and to a 8 times 12 el NBS homemade yagis. I was active with MS and EME on 2 M until 1983.
There was a long time of QRT between 1983 to 2011. Since May 2011 are I on the air again and not surprised that many of the guys from 70-80'ts still is there. The thrill and excitement is still living for ham radio. The video to the right is recorded 2013 by TV4 in sweden
My QTH is now about 8 Km north of Karlstad centrums on a little hill called Skare mountain 75 M ASL (not much to montain hi hi) and I have a 18 m Versatower for the antennas
I am using a Kenwood TS-2000 as main tranceiver. SDR-play RSPdx is used to spectrum veiw and QMAP. My preamps are one MKU LNA 144 A for 2 m and two MKU LNA 432 A for 70 cm from KHUNE electronic. Power Amplifiers are home made LDMOS with 600W on 70 cm and 1000W on 2 m.







Antennas 2026-03-27 2 m 6X11 YU7EF and 4x26 el YU1CF on 70 cm. Stacking for very low ground noise in elevation on 2 m. First side lobe -19,6 dB


Antenna modelling for the array above done with EZNEC Pro/2 v7.0
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144 MHz scanning of ground noise from 0 to 54 degrees elevation
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70 cm EME Antenna 2025-07-07
Same configuration with only 6x26 el YU1CF

Antenna modelling for the array above done with EZNEC Pro/2 v7.0
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Construction of YU7EF EF0211B for 2 m
Boom correction:
For elementholder in pictures below and 8 mm elements, 9,5 mm above boom make elements 7 mm longer for 35 mm square boom and 5 mm longer for 30 mm square boom

VNA measurements on SWR on the antenna



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Building 24 el 70 cm antennas on 6,3 m boom on a square boom 35 mm
The model for the antennas is taken from YU7EF EF7024 24 el with 6 mm element diameter in free space. https://yu7ef.com/ef7024.htm
First did I have to recalculate the length for all elements to 8 mm diameters see simulations made with EZNEC for 8 mm elements and 12 mm dipole




I I did first build a smaller antenna to try out the approximate boom correction for this type of element holders with the element placed about 9,5 mm above the 35 mm diameter boom.



VNA measurements on first try out with 16 mm boom correction and the final result with 12,5mm boom correction
16 mm element boomcorrection


16
12,5 mm element boomcorrection

Some old Antennas


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