Lazy Man's Flex-6500 to Quadra Amplifier Interface

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  • Updated 5 years ago
Hi, I am new to the forum and flex radio's in general. I purchased my Flex-6500 last month and have been very happy with it. I do have some questions for you long time Flex users but will post them separately later. This post will only be about my experience interfacing the 6500 and quadra.

Ok, previous to the new 6500 I was running a Yaesu FT-920 with a Quadra Amplifer. I am planning to keep my Yaesu equipment, so I wanted to be able to include the 6500 in line with the Quadra amplifier and still have automated band changes on the quadra when changing bands on my 6500. I did not want to make up a new interface cable at this time......because as the title indicates and my wife can back me up on this......I'M LAZY. Also from communicating with Flex it looks like we will soon have an interface from the radio to other equipment which will include the ability to automate band changes on amplifiers that allow this.

So my first pass at the lazy man's interface for automating the quadra band changes was to do the following. I simply connected the FT920 to inputs 2 on the quadra and connected the Flex to inputs 1 on the quadra. I then connected the band data cable from the FT920 to band data input 1 on the quadra instead of band data input 2. I used this setup to switch the quadra band by pressing the band selection on the front of the FT920 to match whatever band I was currently transmitting on with the 6500. This was ok but as you can imagine it really wasn't lazy enough, so I started reading some of the previous postings on here and learned about DDUTIL.

I soon found that I could setup DDUTIL version 3 to pass the Flex transmit frequency to the FT920 through the serial cable that I was already using with my logging software. I kept the same cable connections described above, but changed the logging software to interface with the Flex through the SDRCATprogram. I then setup DDUTIL to slave the FT920 with the 6500. Now when I select a new band with the logging software or with the 6500 directly, DDUTIL will pass the frequency to the FT920 and the FT920 will change the band on the quadra.

With the FT920 connected to the quadra I can also listen to my Flex transmitted signal. It maxes out at around S9+20 on the FT920 meter wheather I'm running a few watts or 500 watts. Just make sure you have both radios connected to the quadra inputs and not to a different antenna or you may blow your radios front end transmitting at high power.

I would imagine you could use this same setup with any Yaesu radio that interfaces with the quadra using a band data cable. Well this is my lazy man setup. Just remember to test everything at low power......start out testing with 1 watt and work your way up before going at it full tilt just to make sure you didn't forget something. 73
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Mark Smith - KB5KYX

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Posted 5 years ago

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