Подключение трансвертера от EU2AV к трансиверу Hermes-Lite
Авточехол 26
Есть 3 разъема MMCCC на трансвертере:
1. RX
В связи с этим вопрос, Куда в гермесе подключать RX и TX?
Graeme Jury
Mike Lewis
You need to know the drive level of the TX. If it is 17dBm or less then the low power output RF1 is best. Rx is best brought in on the RF3 connection. If you have the IO board installed, use the Aux RF SMA.
You can use the ANT connector for RX or TX, but use for RX can be risky if you happen to TX into it, and when used for TX, can be risky if you put several watts into a Xvtr connector designed for low power like 0 or 17dBm.
You may need to use attenuators for TX and maybe RX to get things dialed in. With external cabling it is easy to use SMA attenuators. IF using the CL1 at the ref input, check the drive levels are compatible, they likely are. For the CL2 input from my shack 10MHz system, I use a 3 or 6dB attenuator to prevent overdriving the CL2 input.
You will also need PTT. You can use the EXTTR signal on the RCA jack or on the header inside. If you have the IO board you can also pass it through one of the buffer transistors on the board.
The IO board brings out RF3 to the Aux RF SMA connector. If you do not have the IO board then you can run some RG-316 or UT-085 from the internal header to the back panel.
Update: I took at look at the EU2AV 2022 transverter design. VHF Anvelina 144-146Mgz.pdf. I am assuming you are asking about this version.
There is an attenuator at both the RX and TX jacks so you can adjust the resistor values to suit your needs.
TX IF signal goes through the 4dB Pi attenuator, then through K3 directly into filter F1 (RLP50+), then though a 1dB Pi attenuator into the mixer.
The RLP-50+ is a low pass filter from Mini-Circuits, datasheet is here. RLP-50+.pdf. Its insertion loss is about 0.7dB at 21Mhz IF. For TX path, the total attenuation is thus 5.7dB going into the mixer. I only see datasheets for the SYM-18H and SYM-18H+. The SYM-18H is a +17dBm device so the HL2 low power output at +17dBm will reach the mixer at 11.3dBm, well below the device limit so you should be OK to directly connect the HL2 RF1 to the TX input. If the mixer is not an H version then +7dBm or so is likely the limit and you would want to attenuate the TX drive another 5 or 6dBm.
Before I had an IO board I used UT-085 to bring out RF connections I needed to the back panel. The other parts in this picture are a MCP23017 I2C port expander and ULN2803A buffer stacked on it driving a stack of transverters via an external band decoder. This has been replaced by the N2ADR IO Board.
The last config action you will need is to set the right CL1 output frequency which is listed at 122.88 MHz on the drawing. You can do this through a modification to the Hemerlite.py script or some SDR programs support configuring and setting this for you. Thetis, Quisk and maybe some others. Quisk can leverage the hermeslite.py script at startup.
- Mike K7MDL
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