"The keying interrupt must be provided by the ATU in order to avoid hot switching the ATU relays when it tunes. This cannot be determined anywhere but in the ATU, thus it must provide the break. That key line break is pretty important to the life of the ATU."
Thanks to Jack and Dick for pointing out the flaw in my proposal. However, I still don't know of any other remote tuner than provides an amplifier keying interrupt. Are there any? If not, how do those QRO remote tuners survive? Wouldn't it be possible for KAT500 firmware to inhibit tuning when the input power exceeded a safe level? Isn't that protection included now? It would seem to be a requirement very similar to maximum power for key line interrupt - "When your KAT500 starts to tune, because of a band or antenna switch, a TUNE button press, or auto tune based on VSWR threshold, it waits for the transmit power to drop below this "Amplifier Key Interrupt Power", then it interrupts the amplifier key line, waits for a tune-level signal from the transceiver, and selects the appropriate relay settings. " 73, Andy k3wyc ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com