My first adventure with the eggbeater antenna took place 1 year ago when I made this antenna for 137Mhz weather satellites.
Few months ago I tried to listen the satellites trasmitting on 2 m band. So, I modified the old antenna for new frequency, this time using a Rig Expert AA230 for final testing.
I was inspired from documentation writen by ON6WG/F5VIF (you can download from his website, https://on6wg.pagesperso-orange.fr/Page%201.html).
For building the loops I used flat aluminium (15 x 2 mm), you can find in bricolaje store at 2.6 meters lenght. The circumference of the loops is 212 cm. For mounting, I used 50 mm pvc water pipes and textolit.
The ground reflector was made with 8mm aluminium rods, 4 pcs x 53 cm lenght, conected in center and mounted at 27 cm under loops.
The most important job was the feeding harness. I used the ON6WG recommendation (https://on6wg.pagesperso-orange.fr/Doc/Appendix%20A%20-%20English.pdf)
You can find on page 3 all the formulas you need to calculate all the dimensions. I used RG58, because is very hard to insert H1000 or other low loss cables into 50 mm pvc pipe.
So, nothing new. What can I add to ON6WG work are the AA230 tests.
It is an antenna easy to build, does not require adjustments, if you read carefully the documentation. The results "can" be listen...
73's, Cristian - YO4DFT
FT920 - data conector pinout
SCU-17 conector pinout (As viewed from rear panel, not from cable!)
FT-920 pin 1 Data IN (Audio IN) SCU-17 pin 1 Data OUT (Audio OUT)
FT-920 pin 2 GND SCU-17 pin 2 GND
FT-920 pin 3 PTT SCU-17 pin 3 PTT
FT-920 pin 4 Data OUT (Audio OUT) SCU-17 pin 5 Data IN (Audio IN)
FT-920 pin 5 Busy SCU-17 pin 6 SQL IN (Busy)
Pin 1 (AFSK Input):
Connect this pin to your TNC’s “AFSK Out” or “Mic Audio” output line. The optimum input level is 30mV rms, and the input impedance is 3 k. Your TNC’s audio output level potentiometer will allow you to set the level to the optimum value. This pinmay be used either for 300 baud SSB-mode digital operation or for 1200-baud FM packet. The bandwidth and frequency response are not, however, suitable for 9600 baud operation. Be sure the AFSK-FSK switch on the rear panel is in the AFSK position. For FSK operation (whereby the TNC closes a line to ground to accomplish teletype keying), set the AFSK-FSK switch to FSK, and connect your
TNC’s FSK keying line to Pin 1.
Pin 2 (Ground):
Connect this to the shield(s) of the cable(s) used for connections between the TNC and the FT-920.
Pin 3 (PTT):
Connect this pin to the PTT line from the TNC. This pin, when grounded by the TNC, places the FT-920 into the Transmit condition.
Pin 4 (Audio Out):
Connect this pin to your TNC’s “RX Audio” input line. This is a constant-level (100 mV rms @ 600) audio output line which is not affected by the position of the front-panel AF GAIN control.
Pin 5 (BUSY):
This is a “Squelch Status” pin not generally required for digital mode operation. This pin is held at +5V when the squelch is open, and is grounded when the receiver is muted by the squelch (“nosignal” condition).
FT920 Menu settings (dont forget - USB-DATA mode)
Menu # Description Value for WSPR/FT4/FT8/RTTY
U-45 Packet Freq. Display Offset 0000
U-46 Packet Subcarrier Frequency 2125U
Please note, those values are available for regular rtty tones (2295/2125).