How can one connect a full duplex link to a node, such that, even if the radio is receiving, i.e. COR is active, it is possible to PTT the radio?
For example, this could be the case if a repeater is receiving constantly one does not want to inhibit PTT from ALS,
The other case could be where the node is connected to an HF radio but do not want to use the radio squelch to activate the COR input but to rather to be able to listen remotely to the receiver and then transmit as desired.
Chris, ZS6GM
If any connection/node is half duplex, that node is stuck with half duplex.
Yes, it is possible but generally…
It takes 2 radios or a separate TX and RX units.
Transceiver not a option unless the radio is capable of full duplex. Being that it has individual units that can be split and run at the same time…
We use to be able to split Motorola Micor and Mitrec radios for repeater use.
This is possible but with cor active all the time the other node will be txing all the time.
Need a high duty cycle txer. Or you will likely burn it up. Some who use HT’s eliminate the final amp and run on 10-80mw without issue, but you need to know in advance it will work and how to do it with your radio.
A hf rig can be set at half duplex mode and can tx when told. But not rx at the same time.
But you connect to that node in ‘monitor mode’ and it will never tx.
However anyone else listening will hear both. But you can use a setting that reduces monitor volume when there is a active tx.
Hi Mike, thanks for the explanation. I may have not explained myself properly.
If I connect a node to the HF radio, receiving continuously then the node will be transmitting the audio to another remote node. This then prevents the remote from transmitting, i.e. activating the PTT on the HF radio until the COR line is dropped. Is there any way to configure the node to ignore the COR input from the radio so that the remote node can activate the PTT irrespective of the state of the COR on the HF Radio.
73
Chris
Sounds like your hf radio needs a syllabic squelch which is how I do hf remote. Gives the equivalent of COS signal
GeorgeC w2db
Hi George, I have a syllabic squelch a la Motorola Micom. It works reasonably well but I am trying to find out how to make the HF radio end of the node duplex so that the COS cannot override the PTT inhibit. Chris ZS6GM
Trying to visualize this. COS(from HF?) cannot override PTT inhibit (PTT on HF? and inhibit from where?). The way I did it was to treat the HF as a simplex node. It would transmit whenever a network signal came in from the connected node. And while i was in transmit more, naturally, it could not assert COS
GeorgeC W2DB
Yes, this would be true for other half duplex connections.
Nothing I know of to solve that.
The system was originally designed for full duplex repeaters and somewhere along the way half duplex was added for rf links and relay through hard wired controllers etc…
The fact HD can be used to access the system is not really a feature, but a symptom.
The system is full duplex no matter if all the connecting nodes are half duplex.
If you were to trick it otherwise, how would you hear ?
Best result are obtained with full duplex as designed.
Since most using this mode are using HT’s, it means adding a second one on split freq and running full duplex.
George, thanks for your reply. I still seem to have not explained myself properly.
Imagine an HF radio which is simplex in nature, i.e. you are able to receive or transmit. When receiving you can press the PTT and the radio will transmit whether receiving a signal or not.
Now connect this radio to a duplex radio link. The output of the HF radio is connected to the radio link TX, such that the link radio is keyed on reception of a signal on HF. Go one step further, if the HF radio squeclch is lifted continuously, the link transmitter will stay keyed and you will listen to the HF RX permanently. If the link radio were a simplex radio, one would be unable to key the HF transmitter if it’s squelch was open.
However, if one uses a duplex link (not half duplex), keying the TX at the remote radio would be received by the link receiver (not being affected by the link TX state) whose COS would then key the HF radio, overriding the open squelch on the HF receiver.
I’m imaging an ASL node operating in FULL Duplex - not half duplex - in other words the node can transmit and receive simultaneously.
Remote node connects to this HF connected node, and immediately hears the audio output of the HF receiver. If the remote wants to transmit on HF, it does not need to wait for the receive signal to drop but can transmit to the HF node independent of the status of the HF node. Exactly as if it was a full duplex radio link.
I hope this convoluted reply helps to explain.
73
Chris ZS6GM
Is the remote node full or half duplex ? That is the only part you have not been clear on.
I have been assuming from previous statements it was half.(a simplex node)
I’m new to ASL so I’m not sure how to configure the remote link for full duplex operation so that the entire ASL path from HF radio to remote node is duplex
Chris ZS6GM
AllStar is very easy to use for remote rig control. AllStar nodes have 2 audio paths, one between the local audio/radio interface, and the other over IAX that goes over the internet. The ASL duplex parameter refers only to the local radio interface. IAX is always full-duplex.
At the rig you could use something like an AllScan URI110 or URI200 to connect to the HF rig. You will then want to set duplex=3 in rpt.conf so that if the remote node keys up, the HF node will then in fact assert PTT. Then on the remote node side you could use a radio-less interface such as an AllScan UCI120 which you can plug an standard mic and speaker directly into. The UCI120 has better audio quality than RF nodes and is full-duplex, and also uses duplex=3 (which does not repeat Rx audio to Tx). The AllScan.info website has how-to guides showing the exact ASL settings needed.
@zs6gm, all I have been trying to point out is that if a connected node is
half duplex/simplex node, for as long as there is a cor anywhere in the connection path,
it (simplex node /link ) will not be able to tx.
That is not a issue with software, but physical hardware.
HF RB (cor) > SYSTEM (all TX)
SYSTEM (all tx) > SIMPLEX NODE(tx) > Your HT to the link (can tx, but nothing listening, as the listening node is in tx )
That may be as simple as I can state it for understanding no matter what pieces you are configuring and you can calculate the rest.
Perhaps this still is not the config you are running.
I am only trying to caution you from trying what can not be done with just software.
If that is a correct config and you want a cure to make it work with hardware, we can help with that.
Thank you for the suggestions. I will have a go this weekend. Hardware is not the issue, but it is the software that I’m still trying to get my head around. Ivé been doing radio engineering for 50 years but the ASL and similar software based systems are still a bit of challenge. @NR9V and @Mike, thanks for you suggestions, I think I may now have a light bulb moment. 73 Chris ZS6GM