Quantar U453 fast key up option question

[adlertom]

Does anyone know if the U453 fast key up option is strictly for the data controller in an IVD network? I'm wondering if it would be a desirable and usable option for a conventional linked repeater system, in order to minimize keyup delays.

Thanks,

Tom

[Bill_G]

With the fast keyup option, Quantars have keyup times in the <<20ms range (similar to Spectra), and are good for polled FSK systems. The real bugger with Quantars is the latentcy they introduce with their audio processing which is on the order of 5ms. You can pass 2400 and 4800 modem tones over the air through a Quantar without modification, but you will have to add some time pads for the turn around because of how it handles mod / demod. Humans will not notice an advantage with fast keyup, but serial comm over the air will.

[adlertom]

With the fast keyup option, Quantars have keyup times in the <<20ms range (similar to Spectra), and are good for polled FSK systems. The real bugger with Quantars is the latentcy they introduce with their audio processing which is on the order of 5ms. You can pass 2400 and 4800 modem tones over the air through a Quantar without modification, but you will have to add some time pads for the turn around because of how it handles mod / demod. Humans will not notice an advantage with fast keyup, but serial comm over the air will.

Bill,

Do you know what the regular keyup time is (without the U453 option)?

Tom

[Bill_G]

Still pretty fast. Less than 40mS. You can check it with a dual trace scope triggered off PTT and a sensor port off the wattmeter.