[AReU] Next AREU meeting

[w4tas]

I hope this gets through to all of you fine folks. It seems they changed 
the mailing address. I'm sure that the new operating system will be 
an improvement although I had no problems with the old one. 

I am thinking the AREU meeting will be Jan. 01, 02. That's neat don't 
you think? 

I am thinking that Ed will be out of town but I'm not sure. He's such 
a flighty person that you just never know. 

Anyway, I have built a small inverter to get up to 24 volts from 12 volts 
without a transformer. will use it for running 2.4 GHz converters that 
use 18 volts instead of 12 volts for their supply voltage. It can support 
loads up to 500 ma. I plan to build another one that is even smaller that 
uses a lot of surface mounted components. I don't know yet what the 
current capacity of the smaller unit will be. It depends on how creative 
I can get with getting rid of the heat. 

The existing unit is about 80% efficient at full load and doesn't get very 
hot. It is mounted in a very sturdy box for use in the field and size 
didn't matter very much when I was building it. I am using a linear-three 
terminal regulator to get regulated 18 volts because the ripple coming off 
of the raw 23 volts of the inverter contained about 1 volt "peak to peak" 
of ripple at full load. The chop frequency is about 8000 Hz. 

Old Jim (very dry martini) donated a 2.4 GHz dish to Ed the other day. 
I thought Ed was gonna have a fit. He has already mounted the converter 
on the dish and it is ready to go. Maybe we will try it out at a future 
meeting as AO 40 is in a state of hibernation at present. The spin 
stabilization system that is being used requires that the satellite be 
oriented such that the antenna pointing angles are not suitable for 
communications in order to get a favorable sun angle for the 
solar panels. Things will improve gradually until April when the 
satellite will return to normal. At this time or in the not too distant 
future, the momentum wheels will hopefully be deployed and 
things will really get good. 

I have converted both of the California Amplifier converters that 
I got from Al (WD4A) at the last AREU meeting. One of them 
has a 144 MHz IF output but the other is still stuck on 122 MHz 
until I get a crystal in from International Crystal Co. They both 
do a great job however no matter what the IF frequency. I will 
go over the changes I made at the January meeting. 

Hope everyone had a Merry Christmas and are looking forward 
to a prosperous and happy new year. 

73

Tony