Hi all,
I'm using an FT-897D for TX (non-duplex), and an Airspy and computer for RX. Good idea to use four switches Greg, in fact that's what I'm currently doing. With four switches you always use one antenna for RX and the other for TX though, I want to be able to use the same antenna for RX and TX when that works better with the current satellite orientation. Using two switches and two diplexers I would be able to independently select which antenna to use for RX, and which one to use for TX. I posted the connection scheme on twitter (warning, mspaint ahead): https://twitter.com/PA3RVG/status/950649511935905792
But we are drifting from the original question: which diplexers? I have heard good stories about the MFJ-916, but its availability is not great in Europe. What about Comet, Diamond or Wimo? Are they any good?
Regards, Rico
On Mon, Jan 8, 2018 at 11:04 PM, Greg D ko6th.greg@gmail.com wrote:
But he has two cables going into the antenna (you can see them in the picture).
I'm guessing by his hashtags that one of the radios is an RTLSDR dongle, so I can see the need for two cables and the switching from one "rig" to the other. Presuming the other radio is not full-duplex.
Perhaps the answer is to use 4 switches. One pair for the rigs, the other for the antennas. Hook one side of the switched side directly through, the other cross-connected. Just remember to set all 4 switches properly before transmitting!
Greg KO6TH
Brad Brooks wrote:
I reckon the duplexer is required as there is no direct connections to the 70cm antenna.
Brad WF7T
On Jan 8, 2018, 3:20 PM -0600, Greg D ko6th.greg@gmail.com, wrote:
Hi Rico,
So, two questions:
First, what are you planning to use for your radio(s)? I'm a bit puzzled by the need to swap Tx and Rx connections, if you are using a diplexer. And, most of the satellite operations I do involve either two separate radios, or a satellite radio that has separate VHF and UHF antenna connections. In those cases, you'd not need the diplexer at all, since the purpose of a diplexer is to use one feed line to cover two antennas. Could you share your "two diplexers and two switches" diagram?
Second, that's a really cool antenna that you have built. Are the plans available online somewhere?
Greg KO6TH
Rico van Genugten wrote:
Hi all,
I'm slowly assembling my satellite base station setup bit by bit, I
have
recently mounted an antenna system on my roof consisting of two perpendicular VHF/UHF open-sleeve yagi's mounted at a fixed elevation of 25 degrees on an azimuth rotator, more info here: https://twitter.com/PA3RVG/status/942710621375815680
So I have two feed lines coming into the house, both suitable for VHF and UHF operation. I want to be able to independently select one of the two antennas for RX and TX. This can be realized using two diplexers and
two
switches, but now for the million dollar question: Which diplexer?
I'm curious to know which diplexers you guys use if you use them, and which can be recommended in terms of insertion loss, VSWR and isolation. If you believe the manufacturer specifications they are all great, but I'm
more
interested in real life performance or test measurements.
73, Rico PA3RVG _______________________________________________ Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb