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Yoram Rotbach's avatar

Hi,

While the Icom ID-1 is long gone, the IC-9700 and the IC-905 have the ability to use DStar DD mode with a 128 KBps rate.

As I own both radios, I've experimented with setting up a link on the 23cm band. It works as expected, however the rapid TX/RX switching sound using mechanical relays is quite annoying. Why Icom used mechanical relays and not some PIN diode for TX/RX switching is beyond me.

73 de Yoram 4Z1YR

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Chuck Till's avatar

Let me call to your attention the recent telecom experience in western North Carolina after Hurricane Helene. AT&T and Verizon have been soliciting PTT business and investing in network robustness. Nevertheless, about 80% of their networks in the affected area went down. Not just for a day. For five to ten days. In one county, 19 out of 20 cellsites were down for a week.

Why? Most cellsites are now connected to the network core with fiber cables instead of digital microwave which could no longer handle the volume of data. All those fiber cables crossed creeks and rivers underneath highway and railroad bridges. But hundreds of government-maintained bridges, thousands of privately owned bridges, and entire railroad lines for mile after mile were washed out. All those fiber cables were broken.

Worse, the destruction of so many bridges meant that cellsites could not be reached by road to replenish the diesel fuel in their backup generators. So even the cellsites that still had fiber connectivity went dark when their fuel depleted.

The state-run 800 MHz network for first responders and emergency management, known as Viper, performed better. However, even they had problems getting fuel to some radio sites. At some places, fuel had to be helicoptered in and fuel drums were being manhandled through mud in order to keep their network somewhat operational. By intent, Viper does not handle "health and welfare" traffic.

Who came out smelling good in all this? Lowly ham radio. A repeater on Mount Mitchell, the highest point east of the Rockies, played a very important role early on. I spent a day relaying messages off HF to NC Emergency Management HQ here in Raleigh. What eventually saved the day was helicopter delivery of enough Starlink terminals into the affected area to handle the traffic.

NCEM is considered one of the best emergency management agencies, and their experience over the last 10 years with hurricane flooding in eastern NC had indicated that Viper and the public networks were sufficiently robust. Ain't so.

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