IC910 Volts up coax before Tx?

[VK2GOM]

Just wondering if anyone knows for sure if the IC910 has built-in rudimentary sequencing, that being when pressing the PTT (or triggering the Tx line on the Acc socket) there is a couple of mSec delay to ensure the 12V up the coax to the preamp relays allows them to switch and de-bounce before RF appears?

Out of interest, the old Icom IC820 has a built in sequence delay on the pre-amp switch. I'm wondering if this has been carried across onto the IC910 design?

73 - Rob VK2GOM / GW0MOH

[VK3PF]

Rob,

I have not checked the details, but the AG-25 etc preamps are also sold as compatible with the IC-910 & the IC-9100. This family of preamps is fed by volts up the coax on Rx, so presumably the delay is built into the transceiver design. From memory, the relays only activate if the Tx/Rx is in Rx mode AND the Preamp button is selected, which enables switching of the relays to enable the preamp when in Rx.

Regards,

Peter VK3PF

[VK3BA]

I concur with Peter.

We regularly use my IC-910H for FD's using home-brew masthead preamps for 144 & 432 and everything works fine. The RX preamp is activated when the radio is sitting in RX mode. Once the functions (per band) are selected in the radio, it works like a treat. Makes a world of difference.

Cheers,

[VK2GOM]

Thanks for the info chaps; I'm aware of the fact it works since I have used my 2m masthead preamp by this method, but I'm just wondering the electrical specifics of the Volts up the coax - does it occur a couple of milliseconds before the ALC lets the RF appear, or not? The IC820 did, so I assume this does. Or might! I might need to rig up a test setup and try and capture it on the scope.

73 - Rob VK2GOM / GW0MOH