Happenings

We all like to hear what other hams are up to, and we'd love for you to share some of the fun projects you've been involved in.  That's what the weekly round table discussion is for, but if you've got something noteworthy you'd like to share here too -- especially if you have pictures -- just email me the information.

Also, news of upcoming events is posted to this page.

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Power Supply Repairs

posted Nov 4, 2020, 11:37 PM by Charles Boling   [ updated Nov 4, 2020, 11:38 PM ]

Something over a decade ago, Ray bought VHF radios for all of the units in the stake and put them in the church buildings with antennas & other things needed to set up a field-expedient radio station. All of the power supplies are the same model, Samlex SEC-1223. In 2014, one of the supplies started making noise, and I determined that the cause was a set of failed capacitors. As I wrote at the time:
for several years around the turn of the century several Taiwanese
manufacturers used some bad formulas for the electrolyte in their caps
that rotted them, and millions were put on the market with severely
shortened life -- in some cases as little as a few months.  It was a
huge deal, w/ computer manufacturers like Dell taking a lot of heat and
losing a ton of money having to replace failed motherboards (I know one
guy who had a board w/ over 30 failed caps on it), and "re-capping"
high-end boards became a lively business.  That pretty much all blew
over after the 1st decade, but I suspect that these caps were part of
that group.
More testing:
Power supply open w/ arrow indicating problem caps

I tested the supply, and the output is still pretty good -- 13.8V drops
to 12.7V under 70W load w/ <1V ripple -- so I don't think any other
components are damaged yet.

I put it on a scope and confirmed that without a load there's a lot of
pseudo-random noise on it; with a slight load it stabilizes to a 2-tone
waveform w/ the primary frequency around 50kHz (I didn't bother to
measure it carefully -- just going from memory of approximate size on
screen and dial settings) and the 2nd an octave up and almost as strong
(any higher harmonics weren't obvious) with ~20% jitter.  Putting a
~60-70W load on it (my radio transmitting on high) made it go bananas,
with a large variance in amplitude and frequency, peaking at over 1V.  I
listened on another radio while transmitting and verified that no lower
frequency components were making it through unfiltered by my rig (an
IC-208H).

These 3 caps just sit across the outputs to stabilize it and work w/ the
chokes to get rid of the last of the ripples, so they don't directly
affect most of the circuit and unless they short instead of open they
shouldn't do catastrophic damage unless the inductors don't choke enough
and allow higher-voltage spikes somewhere that take out something more
important.  Judging from what I saw on the scope, that probably won't
happen, but it's possible that it would throw something upstream off
just enough to destabilize the PWM chip or something so it shouldn't be
used until they're replaced.

I found someone else who had the same problem
and learned from his mistake to measure the physical size of my caps
instead of believing the 16x25mm specs.  Sure enough, with the change in
board layout (ours is 3 in a straight line, but all the official pics
show one offset w/ inductors in the corner where it might otherwise be)
they tightened the spacing, and the 16mm won't fit!

Equivalent caps are about $1 each:

It was a good education for Alexander as I led him through the process of testing and fixing it.

Apparently, that radio was used more than the others.  Fast forward 6 years to last Sunday...
It was pretty funny today. Remember during the exercise when the Castle
Alexander &amp; Steven working on the PS

Rock radio wasn't working right?  Bp Morkert brought it to me at the
stake ctr today so I could inspect & test it, trading parts (e.g.
microphone) w/ another radio if needed. I pulled the stake radio out to
use as a receiver, turned on its power supply, and poof! Smoke began
pouring out. "Not worries -- I have another one!" I pulled out the
Longview 3rd radio, turned it on, and a few seconds later *it* began
producing smoke!  All 3 supplies were emitting a complex sound that,
well, sounded like a classic failing switching supply.

CR's supply isn't smoking yet, but it's putting out bad power. The radio
can transmit @ 5W w/o noticeable artifacts on the received audio, but as
the power draw goes up it gets worse. Needless to say, Bro. Morkert
didn't return with a radio...

I'm going to open them up and inspect them, and assuming that it's what
I think it is, I'll order enough caps to do all the radios in the stake.
 Once these are back in operation, I'll start pulling the remaining
working radios and replace the caps *before* the supplies fail....
My middle boys are going to get a lot of soldering
practice, and Alexander's going to be doing a lot of teaching.

I ordered 30 more capacitors, and Alexander & Steven fixed those 3 radios this evening. That's a total of 4 down and 6 to go! A good education for Steven; I think I'll have William help with the next few that come in.

Thurs Jul 30 Simplex Exercise

posted Jun 28, 2020, 12:23 PM by Charles Boling   [ updated Jul 30, 2020, 6:32 PM ]

OTVARC Mascot

The Oregon Tualatin Valley Amateur Radio Club has invited us to participate in their 5th Thursday Simplex Contest (previously the Fifth Wednesday Simplex Contest) starting July 30th @ 7PM (don't be late!) on 147.54 MHz FM.

This opportunity to participate with OTVARC will replace this quarter's regional ERC simplex exercise, and I encourage everyone who's free that evening to join us! Each station should keep a log of who they hear (there's a log sheet on the page linked to above), and submit it afterwards so we can see who can talk to whom. Paul Gerke, KF7SKD from Vanc. West Stake, has volunteered to sift through the reports; please email your results to both otvarc@gmail.com and kf7skd@qsl.net. When Paul's finished with his analysis, we'll see that all participants get a copy.

ERC Goals

  • Exercise your skills (esp. listening)
  • Test your equipment (emergency power, anyone?)
  • Map all the propagation paths -- who can hear whom

Operating Hints

  • Open your squelch so that you can hear weaker stations
  • Make sure you're in simplex mode (no TX shift)
  • Listen so you can get a feel for the protocol, but don't be afraid to transmit!
  • Get on early, if possible, so you don't miss anything

Logging

  • In the notes, please include a 2-digit "RS" signal report for each station heard
    • 1st digit = Readability
      • 1 = Detected but 100% unreadable
      • 2 = Occasional words understood
      • 3 = Readable w/ considerable difficulty
      • 4 = Easy copy
      • 5 = Perfect (full quieting)
    • 2nd digit - Strength
      • 1-9 (use your S-meter if possible)
      • 1 = Barely detectable
      • 9 - Extremely strong
      • If you submit a reading outside 1-9 (e.g. "0" or "S9+60") we'll probably clamp it to the 1-9 range when we aggregate the statistics.

Update:
I added an alternate log sheet, in OpenDocument Spreadsheet and PDF formats. You may find the spreadsheet a lot more convenient to use.
When done, you could export it to PDF and attach both formats so Paul and OTVARC can choose which they want to work with depending on what they're doing (printing/viewing vs. extracting data)

Simplex Nets canceled

posted May 24, 2020, 10:27 AM by Charles Boling

The Thursday & Sunday simplex nets, a/k/a "The Charles, Lloyd & Kevin net", has been canceled for lack of participation. It was a fun experiment, and I did enjoy getting to talk to my two net buddies more than once a week!

Simplex Nets

posted Mar 28, 2020, 1:35 PM by Charles Boling

To allow more opportunities for us to connect on the air -- and to stretch our simplex muscles -- we're going to add two VHF simplex nets during the week:
  • Sundays 9:30-9:45 AM
  • Thursdays 5:45-6:00 PM
Both nets will be held on 146.46 MHz. I will transmit a 100 Hz tone, but will keep my squelch open.

These will be semi-formal nets; I will announce them, and will act as net control as needed, but I predict that fewer people will participate than the repeater-based nets, and it may give the chance for more casual conversation. That said, Simplex will be a challenging reach between many points, so if you can help relay, that would be appreciated.

I will stay tuned until the designated ending time, even if there is no activity. If you don't hear anything, please call out!

Based on response, these nets may or may not become a permanent activity, and the times/days may change.

Pre-CCE22

posted Feb 9, 2020, 9:20 PM by Charles Boling

You might find this document to be of interest:

I originally received a copy via CAP. I don't see anything that would contraindicate public dissemination, but I also didn't see it on on any WA websites, so rather than post an actual copy of it here, I'm referencing the copy that ID ARES is hosting, so if someone tells them to take it down, it'll automatically break our link too. :-)

A few key points:
  • Gearing up for Cascadia Rising 2022
  • Comms is being separated a bit, because the biggest comm challenges are likely the first few days after a disaster, whereas the main exercise will focus on later response. (Y'know, we keep telling you not to expect the gov't to be there immediately? The exercises have realistic expectations!)
  • A big part of WA EMD's comms goal is to more fully/consistently use amateurs.
    • Amateurs (on average) have technical skills, i.e. we don't just wring our hands if the radio doesn't work
    • We're more useful if we train w/ served agencies and know common procedures.
      • Consider this a plug for ACS membership and ICS courses!
  • Camp Murray's getting a 220 repeater

Technician study classes in W. Longview

posted Jan 20, 2020, 4:24 PM by Charles Boling

Jeff Edgecomb (KB7PMO) is starting another series of classes to help people prepare to take the technician class amateur exam.  They're being held at 5PM every Tuesday at the meetinghouse at 1721 30th Ave, Longview, WA 98632. Contact Jeff (jmedgecomb at yahoo.com) for more info.

Rainier Stk net

posted Jan 17, 2020, 3:39 PM by Charles Boling

Rainier stake holds an ERC check-in net on a repeater system that includes Nicolai Mtn (146.76), an easy reach for many of us in the area. It's a brief net Sundays at 19:00. More details on the net calendar. We're a good link from the coast inland and in a good position to help each other, so just as we have people from Oregon that check into our nets regularly, it wouldn't hurt for a few of us to be familiar with their group.

FEMA youth camp in Alaska

posted Dec 29, 2019, 5:23 PM by Charles Boling

Region X is hosting a free (even transportation is provided) 6-day camp in AK for teens interested in disaster preparedness. To learn more and apply:

Road trip!

posted Sep 9, 2019, 9:34 AM by Charles Boling

AD7UF and his family are on a 3-month road trip! Covering all 48 states and 8 provinces, there will be opportunities for operating from a lot of neat locations.  While he's not bringing as much gear as he'd like due to time constraints, supply problems, and spousal concerns (Michele wasn't happy when she found out that he was planning to bring his 13-lb. CAP HF rig along!) so he scaled back both radios and antennas, but he's still got enough to be fun and useful.  Focus will be on VHF, since he doesn't have an HF antenna configuration that won't get bridge-whacked, and he will be too busy to do that much operating while stationary.  Basic Amateur gear on the bus includes:
  • Front:
    • Cheap Chinese VHF/UHF radio (QYT KT-8900D) & fairly short dual-band antenna.
  • Rear:
    • Yaesu FT-897 all-band rig. VHF is attached to a 1m dual-band antenna. HF goes to a stud mount that gets a variety of generic Ham Sticks attached. A 1/4mi spool of aluminum fence wire provides the opportunity for a variety of longer antennas.
    • Alinco DR-590T dual-band rig operating primarily as a cross-band repeater for family tactical ops.  It feeds separate UHF & VHF antennas w/ a diplexer on the VHF side acting as a low-pass filter to further reduce self-desensing.
  • Plus:
    • A whole bunch of HTs for portable & supplementary use.
KF7JZN's parents are mostly following along in their motorhome, so radio is useful for commiunicating with them.  They have a KT-8900 with a mag-mount antenna attached to an aluminum cookie sheet (with a magnet on the back to help hold it) on their dash board to supplement their HTs.  Charles brought a laptop (necessary, since he's continuing to work throughout this trip) and programming cables so he can customize the radio memories for each area.  Pictures are promised; check back later!

Ham Radio Basics this Saturday - Vancouver

posted Apr 22, 2019, 12:34 PM by Charles Boling

The Clark County Amateur Radio Club will present a program that covers the basics of ham radio.  We will have presentations on Friday, April 26, from 7-9 PM that will cover radio equipment suggestions, antenna suggestions, and power concepts.  Saturday, April 27, presentations from 9 AM – 1 PM will cover portable operations, opportunities for public service, and help getting on the air.  You can attend one or both days.  The program will be held at The Church of Jesus Christ of Latter-day Saints chapel located at 11101 NE 119th St just West of Winco on the South side.  Note that 119th St is under construction, so watch carefully for the driveways across the dirt (at least it was dirt the last time I visited Winco).

After you enter the parking lot, drive to the south side (away from 119th St) and enter the glass doors.  Turn left and you should see us.

If you plan to attend Saturday, we recommend you bring your handheld if you have one. 

Questions?  Contact Delvin, NS7U.  We hope to see you there.

 

Delvin Bunton, NS7U

President, Clark County Amateur Radio Club

drbunton@comcast.net


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