Pres Says Aug 2025
A Month of ‘Power’
Power – Earthquake!
This past week there was an 8.8M quake in Russia and Tsunami warnings were issued. My seismometer, sitting in my living room 4000 miles away from the epicenter, first picked up the quake approximately 11 minutes after it happened. P-waves, vs S-waves, are the fastest traveling waves from an earthquake. The difference in time between the arrival of P and S waves is how scientists determine how far an earthquake is. By using data from several stations, they can determine the epicenter and magnitude.
As you can see from my seismograph plot above, the Earth was ringing from this quake for over 4 hours (each line is 1 hour). It took that long for the trace to drop to the background noise level for the day. Wow! Also, remember I mentioned it took 11 minutes for the quake to show up on my seismograph? 4000 miles in 11 minutes is over 21,000 miles per hour! Pretty darn cool! Thankfully a deadly Tsunami was not generated, and I think the damage caused by this massive quake was small, but it is a reminder that we’re all connected on this blue ball hurling through the void of Space. Historically, this quake ranks in the top 6 since humans started scientifically measuring quakes and top 16 of all quakes recorded.
This site has videos showing how this 8.8M quake propagated across the Earth. Choose a view to see how far it was felt. https://ds.iris.edu/spud/gmv/23347566
Power – Electrical
At the last club meeting some of you heard me say that I was without power at my house. The problem started the evening before – a resettable breaker built into my pole transformer had tripped, darkening 4 houses connected to it. That night an SCE service person came out, and using a telescoping fiberglass pole, reached up to the transformer and reset the breaker. “If it happens again, I’ll put in a ticket to have your transformer replaced. It’s from the 50’s and probably already on a list to get upgraded.” Yay, I had power again! Until the next evening.
Friday 6pm the power goes out again. A different tech came out and told my wife he was going to have the transformer replaced. When I checked my outage status online, SCE’s showed power would be restored by 1am. “Interesting, they’re going to replace it in the middle of the night” I said to myself. Margaret and I made sure we didn’t open the fridge or freezer and we both went to bed for the night. 1am passed and when I checked the status, it now said service would be restored at 2am. 2am soon passed and the update now showed 8am. At 3am I decided to get up and run backup power to my fridge. From my shed I dragged in two half charged 24V 100AH LFP batteries, a 1200W pure sinewave inverter, cables and fuses, and in less than 10 minutes the fridge was running. Quiet, clean power. No gas generator noise, no smell, no extension cord running through the house. And a perfect test of the high surge capacity inverter I always intended for this purpose but never tried it out. (FYI, the majority of refrigerator compressors have HUGE inrush current needs).
In the morning SCE’s estimate of 8AM became 1PM, then 2PM. Off the horse ranch I went for a ride and when I came home at 11:30am, my street was blocked off and warning signs were placed on the cross streets to let folks know work was being performed, 3 HUGE SCE trucks and several others were on site. At least 8 workers were on the scene. There was even a Spectrum cable service truck nearby I think to make sure their equipment came back up. Power was turned off to my block so work could be done. My old transformer was on the sidewalk, and up on the pole was a new transformer and 2 guys at the top working. Another 2 guys were at the base of the pole helping run parts and tools up and down to the workers. I was impressed. Now I know why they waited until daylight to do the work. I didn’t see how they got the transformer swapped – I think it was all done with ropes and pulleys as there was no boom truck or crane. Shortly after 1PM we again had power, and other than a new transformer on the pole, you could not tell they were there.
What did I learn? SCE crews are friendly (I’m an engineer, of course I talked to them), professional, and don’t cut corners. I also learned that the inverter I got with the hopes to power my fridge did just that without complaint and without a lot of noise (Victron Phoenix 24V 1200W low frequency inverter). The cooling fan on the unit was barely running. If the two batteries were fully charged, they would have been able to supply around 4KWh, or more than 40 hours of power to the fridge. I think I’ll make a rollable power station for this setup.
Power – RF (the lack of)
In my work office I have a Slim Jim antenna hanging from the ceiling and a Btech 25×4 tri-band radio on the desk. They’ve been located there for many years, at the ready for an emergency but meanwhile being used to occasionally check into SBARC’s morning Cuckoo net. Even though my work building is reinforced concrete and built to withstand an airplane crashing into it (we’re on SB airport’s flight path), this setup can get into 3 of SBARC’s linked repeaters and into WD6EBY’s Santa Ynez Peak repeater – until this week. Monday when I tried to check-in, when I unkeyed I heard another conversation already going on. “There must be an issue with this repeater” I thought to myself. Wednesday it happened again. Thursday I tried a different repeater – same thing. Nobody could hear me. Then it dawned on me, maybe I wasn’t putting out any RF power. Sure enough, none of the repeaters I tried could hear me.
I didn’t have a wattmeter at work, but for the heck of it I went ahead and popped the cover off the radio to look at the final PA transistor. It was marked ‘A5M06’ and a Google search showed it was a 6W (!) RF transistor from NXP. This is supposed to be a 25W radio and I’ve measured at least 20W coming out of it before. More Google searches later I find that the board in this radio is used in several different radios, and some only have a 6W transistor fitted and others with a 16W part. I’m used to Chinese radios not putting out full rated power, but I didn’t think some would undersize their parts so badly. Given the large discrepancy, I am surprised this radio lasted as long as it did.
The radio is now at my house waiting to be repaired. Thankfully both the 6W and 16W part are readily available and at $7 for the 16W part, it won’t break the bank. Thank you Digikey for picking up the shipping on prepaid orders, making this repair even cheaper.
You might wonder why I would even fix this vs using a better radio. Well, there are several reasons. It’s quite compact and doesn’t take up much room on my desk. It also has an adjustable mic gain setting, so it’s not your typical “hard to hear” Chinese radio. Lastly, the audio from its speaker is pretty good. So many Chinese mobiles have a constant loud hiss on the audio, making it hard to understand the other person when the volume is turned down low. In a noisy car, you need to turn it way up anyways so you don’t notice the loud background hiss, but in a quiet office setting it’s very obvious and this radio is good on the ears.
Soon this radio will be useable again
What’s Coming Up In August?
Aug 8th, 7pm Friday – Our next club meeting at Grace Lutheran Church. Dr. David Pepper WA6TWA will give a talk on the “History of HAM Radio Callsigns”. Dr. Pepper is a great story teller. This should be a fun meeting!
Aug 9th, 11am – 2pm Saturday – Portable Operations and Help Event at Grace Lutheran Church. As usual, the club will provide fire and water for those wanting to cook themselves something to eat. Come out and set up a radio and operate! Or if you need help with your rig, an antenna, or you just have ham questions, come out and we’ll get you going.
Aug 16-17, Saturday and Sunday – Wings Over Camarillo – this event is still looking for volunteers to act as boots and eyes on the ground. If you volunteer, you’ll get free admission to the event, a shirt, and a free meal! Each day is split up into two shifts, and volunteers will work 1 shift by “strolling through the showgrounds to enjoy the static displays and the airshow above, while providing eyes/ears/comms”.
If you’re interested, contact Eric Schwarm (N6RFI) at (970) 646-8267
See you all at the next club and portable operations meeting!
Dave AI6VX
