This topic probably deserves a bit more in depth coverage. There are many ways to configure antenna switches, some of which could be quite easy to make a mistake with. I use an antenna tuner that has 3 antenna outputs, and the input to this tuner has a 4:1 radio selector switch so four radios can be selected. The antenna tuner switch allows 3 antennas to be used, or two antennas and a dummy load. No matter how the switches are set a transmitter can never feed into a receiver, one antenna feeds one radio and all else is grounded. There are many ways to configure a system but one should avoid connecting a receiver to a transmitter no matter how the controls are set. Adding a dedicated receiving antenna is useful as well, with enough separation and/or protective circuits to prevent damage. 73 de w6akb
Thanks Dave, for this video. I've been wondering how to set up my shack with this in mind. I think I will need to see it in schematic form, however. I have four very different radios that I'd like to switch between two transmitting antennas, probably an end-fed dipole or inverted V once I get it installed on my small property, and a transmitting magnetic loop antenna. Two radios are receive only and I'd like to be able to switch them between the two transmitting antennas and a Mini-whip receive only antenna. The Mini-whip is especially sensitive to strong signals. The radios are an Icom IC-7300 (which I haven't purchased yet), a Kenwood TS-830S hybrid, an SDRPlay-RSPdx, and a Hammarlund HQ-120X SW receiver. I'm particularly worried about the SDR and the Hammarlund as I don't want to damage their front ends even accidentally. Is it possible to transmit on one antenna and let the receivers receive on another, and if so, how do I handle the PTT/Standby switch on the transmitter so the receiving radios' inputs are shorted whenever a transmission is taking place? Thanks! 73 KD2ORG
I have a scanner in my pickup. I also have a 2 meter transmitter. I have noticed while testing that my scanner (bcd536hp) powered off or rebooted when I would transmit on the 2 meter. So I haven't kept them both hooked up since (two separate antennas but left the coax disconnected at the radio). I've been thinking i could use a Dow key, hook the antenna port to the scanner, the NC port to the antenna, and short the NO port. I would just use a switch to control the coil of the Dow Switch and short the scanner coax at the same time "disconnecting" the antenna via the relay. What are your thoughts on this? I really don't want to destroy my scanner!
Dave, even with the MFJ 1708B in line, I still see my tx signal on the SDR play. My question is, am I seeing enough signal to damage my SDR? Please let me know. Thanks, Jeff K7JZI.
What is the model of that unit that you recommended for reducing the signal level into a receiver in your station? I have a direct need for it. I currently have a legal limit AM class E xmtr and am using a Flex 3000 receiver and the xmitted signal is going off scale and I can see distortion products on the Flex 3000 that comes from an overload. I currently use an attenuator to reduce the signal going into the 3000 but it's an extra switch to throw that I would like to avoid Thanks, Al W1VTP
Just got my tech license, this may be an obvious answer, but if I have a Yaesu 991 that has both hf and uhf inputs, is this still an issue if I have both antennas installed near each other, or is it not an issue because it is only one radio?
Man it's so complicated! So much to learn. Very complex. Your a human all data!
This topic probably deserves a bit more in depth coverage. There are many ways to configure antenna switches, some of which could be quite easy to make a mistake with. I use an antenna tuner that has 3 antenna outputs, and the input to this tuner has a 4:1 radio selector switch so four radios can be selected. The antenna tuner switch allows 3 antennas to be used, or two antennas and a dummy load. No matter how the switches are set a transmitter can never feed into a receiver, one antenna feeds one radio and all else is grounded. There are many ways to configure a system but one should avoid connecting a receiver to a transmitter no matter how the controls are set. Adding a dedicated receiving antenna is useful as well, with enough separation and/or protective circuits to prevent damage. 73 de w6akb
What is the brand/model Antenna Tuner you use?
@@sincerelyyours7538 Elecraft KAT500.
Thanks Dave, for this video. I've been wondering how to set up my shack with this in mind. I think I will need to see it in schematic form, however. I have four very different radios that I'd like to switch between two transmitting antennas, probably an end-fed dipole or inverted V once I get it installed on my small property, and a transmitting magnetic loop antenna. Two radios are receive only and I'd like to be able to switch them between the two transmitting antennas and a Mini-whip receive only antenna. The Mini-whip is especially sensitive to strong signals. The radios are an Icom IC-7300 (which I haven't purchased yet), a Kenwood TS-830S hybrid, an SDRPlay-RSPdx, and a Hammarlund HQ-120X SW receiver. I'm particularly worried about the SDR and the Hammarlund as I don't want to damage their front ends even accidentally. Is it possible to transmit on one antenna and let the receivers receive on another, and if so, how do I handle the PTT/Standby switch on the transmitter so the receiving radios' inputs are shorted whenever a transmission is taking place? Thanks! 73 KD2ORG
DX Engineering makes a RTR2 switching box which is great quality
Who makes your antenna switches Dave?. Thanks for reading!
I have a scanner in my pickup. I also have a 2 meter transmitter. I have noticed while testing that my scanner (bcd536hp) powered off or rebooted when I would transmit on the 2 meter. So I haven't kept them both hooked up since (two separate antennas but left the coax disconnected at the radio). I've been thinking i could use a Dow key, hook the antenna port to the scanner, the NC port to the antenna, and short the NO port. I would just use a switch to control the coil of the Dow Switch and short the scanner coax at the same time "disconnecting" the antenna via the relay. What are your thoughts on this? I really don't want to destroy my scanner!
Dave, even with the MFJ 1708B in line, I still see my tx signal on the SDR play. My question is, am I seeing enough signal to damage my SDR? Please let me know. Thanks, Jeff K7JZI.
Thanks, Dave. Always helpful information. 73, AC3HT
What is the model of that unit that you recommended for reducing the signal level into a receiver in your station? I have a direct need for it. I currently have a legal limit AM class E xmtr and am using a Flex 3000 receiver and the xmitted signal is going off scale and I can see distortion products on the Flex 3000 that comes from an overload. I currently use an attenuator to reduce the signal going into the 3000 but it's an extra switch to throw that I would like to avoid
Thanks, Al W1VTP
No, a factor of 1e15 is a quadrillion... a million billion
The giveaway page hasn’t been updated since April. Did I miss something?
The giveaway address doesn't change, so why would it need an update?
Nice........
Just got my tech license, this may be an obvious answer, but if I have a Yaesu 991 that has both hf and uhf inputs, is this still an issue if I have both antennas installed near each other, or is it not an issue because it is only one radio?
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