Bill,

The 530 lets you select one band as the transmit band, and the other as the band that the dial tunes. Simply set the 2m side to the 2m uplink, the 70cm to the downlink + expected doppler shift, set the sub band tune to tune the 70cm side, and then when you push the ptt it will transmit on 2m. The only thing you'll need to touch during the pass is the main tuning knob, and the PTT. This feature is only on the 530, on the 470 you have to swap bands, tune, then swap back before transmitting. With the 470 figure on doing this 5 times on a long pass, and I was always able to do it with one hand, even with gloves standing knee deep in snow in South Dakota.

To answer an earlier question (or to not answer it) I've never had the need or desire to operate a full duplex rig where the receive band mutes on tx. There are cheap earphones that work for full duplex just about everywhere. I still use a pair I picked up for free from JetBlue two years ago. If I'm doing a demo where I want others to hear, like at a hamfest, I have an extension speaker from MFJ (read CHEAP) that I screwed a belt clip from an old cell phone onto, so that it clips to the back of my belt facing the other way from me. This and careful volume control will normally prevent it from squealing due to feedback.

Think about this...full duplex means you can tweak your antenna orientation WHILE transmitting for max signal. All the FM microsats use a single whip for receive, meaning a linear yagi like the Arrow will have ~20db!!! of variation on the uplink due to cross polarization. If on your next dxpedition, would you bring along a 500w amp if it only had the size and weight of a pair of earbud headphones?

73, Drew KO4MA

----- Original Message ----- From: "Bill Dzurilla" billdz.geo@yahoo.com To: amsat-bb@amsat.org Sent: Friday, April 04, 2008 8:20 PM Subject: [amsat-bb] Re: Best HT's for sats?

You mean you have to switch to the receive VFO and then switch back to the uplink VFO every time we need to make a Doppler correction? It's not cold here in Florida, but I can sure see how that would be annoying. Andrew said the FT-530 has a "subband tune function," what about that? 73, Bill

--- Dan O'Barr kl7dr@yahoo.com wrote:

...

Hi Rafael and Bill,

That's the issue with the FT-530, and it's the

same

...

with the Alinco DJ-580. They are both very good radios for full duplex. If you are in a warm climate, and do not have to wear gloves, then all the

button

...

pushing to change back and forth between VHF for transmitting and then to UHF for receiving and changing frequencies for Doppler, then it's no big deal. However, up here the ability to just program 5 spit channels, like the VX-7R,

makes

...

it a lot easier to work a pass. I believe the FT-51 has the capability of working full duplex with a setting that allows the operator to transmit on

one

...

band and receive and tune on the other.

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