New VECOM Vests

Members of VECOM and JCARC are trying on new vests. The vests will be customized with a VECOM tag

Dick (AH6EZ) and Chris (N7ZW) trying on new vests for VECOM: Volunteer Emergency Communications.

Parks on the Air

POTA: Hunting parks, states, and just having fun! 

As a new General I was excited to get on the HF bands. The question was, “Where do I start?”  The answer for me was POTA, Parks on the Air. I had heard about POTA, but really had no idea how involved you could become, the friendships you can make, and how easy it would be to get on the radio regularly, if only for 10 minutes. 

June 4, 2021, I sat down for a quick break and turned on the radio. As I scanned across the 20 m band there was a loud station calling CQ POTA. I quickly gathered myself and waited for him to finish. When I called back, he instantly replied. I was 59 at park K-3194. I thanked him for the 59 and said he was also 59, on the Olympic Peninsula in Western Washington. His reply, I am in Port Townsend at Fort Worden State Park, where are you located? Me, less than a mile away one the hill above you. We both had a good laugh, and I was hooked. He told me to search google for POTA and sign up, you will love it. Well, let us just say he was right. 

Signing up for POTA is quick, easy, and free. Their website (https://parksontheair.com/) is full of useful information about the program for both those who want to be Hunters and those who want to be Activators. Hunters are looking for Activators who are operating mobile at parks, in the mode of their choice, CW, PH or Data, and on band of choice. At this point I have only hunted but look forward to getting out and activating parks in the future. There are links where Activators can post their planned activities, and Hunters can spot Activators that they worked to alert others. Activators post their logs to the site after their activations for credit and thus credit Hunters who were in their log. Many awards are available which are delivered directly to your account as a pdf when earned. The POTA team really has things running smooth. 

Hunting parks has really helped my radio IQ increase. Like everything else, the more you do things the easier they become. I have become much better at adjusting filters on my radio for band conditions, understanding propagation, depending on time of day and band, listening to operators call CQ and learning to reply in a pile up.  

POTA is not a contest, although it is a terrific way to compete with yourself. I am working on my POTA WAS award, have worked 35 states, closing in on my 200 Unique parks award, currently at 164, and have had a total of 195 QSO’s, 155 SSB and 40 Data, on 7 different bands, 80, 40, 30, 17, 20, 15 and 10 meters.  I have also worked 3 DXCC entities and looking forward to more.  I am also looking forward to the next QSO with Rick, K5DGR, who I have had 14 QSO’s with across 4 states. You never know where you are going to fine a familiar call. 

I hope this will encourage you to check out Parks on the Air. Looking forward to hearing you all on the air soon. Who knows, one day the club, W7JCR may do a POTA activation? It could be a fun outing!  

73, N7TPR 

Rich 

Semiconductor Update – Success!

I received some new N-JFETs today from Mouser.com. This time the component tester shows the $4 J310 part as an N channel JFETs, like it is supposed to.

I replaced the burned out resistors in my RF signal amplifier, and installed one of the new J310 FETs. This time before I powered up the circuit, I made one additional check to make sure I did not get smoke again. This is a check that can be used with any circuit, to make sure there’s not some short circuit or other catastrophic problem, and it uses Ohms Law. It only requires a multi-meter.

I measured the resistance across the two power connectors (+ and -) on the circuit board and got 161 ohms. Then I calculated the expected current draw based on using a 12.6v battery using Ohm’s Law:

Because this is a small-signal amplifier (for an HF receiver) I would expect the current draw to be very small–like a fraction of an amp. Anything else would suggest a short-circuit, or some other kind of problem (like a fake part, for example)!

By my calculations, the circuit should draw roughly 78 milliamps, which is a small amount of current–certainly not enough to blow a hole in a transistor like last time! After powering up the circuit, and seeing no smoke… and touching the transistor carefully to make sure it was not getting hot, I turned on the signal generator, and connected it to the input terminals of the amplifier board.

I set the signal generator to send a sine wave signal of 500mv (1/2 of one volt) at a frequency of 2MHz, and connected the oscilloscope to the output terminals of the amplifier board.

The oscilloscope showed the output of the amplifier to be a sine wave of 4 volts, an 8 times increase in voltage. Using the formula of dB=20 x log10(vout/vin) we get 18dB of gain, which is actually more than I was looking for. So I turned the adjustment potentiometer on the circuit board which changes the voltage on the gate of the N-JFET transistor, and reduced the voltage of the output to 2 volts, giving us a 12dB boost, which is what I was looking for.

I did one final test of this circuit. I had also purchased a bag of 100 cheaper N-JFETs (J113), costing about 25 cents each. (I bought these from mouser.com). I wanted to see if the circuit performed any differently with the cheap part, versus the much more expensive part.

Let’s see: $4 versus $0.25 would be a 16 times decrease in price, or -24dBd (dB in dollars. That’s a joke)

The end result is that the circuit performed identically with the cheaper part. Even the frequency cutoff was the same. Go figure… 73

Don’t get Burned by Cheap Semiconductors!

Last week I finished building an amplifier circuit board that will eventually be part of an SSB transceiver that I’m designing and building. After double and triple checking the board, I applied power… and heard a “pop” sound, followed by a little cloud of smoke. There was small hole blown out the side of the FET (Field Effect Transistor) on the board, and two of the resistors had been burned out–literally looking charbroiled. What in the world happened?

I checked the remaining supply of FETs that I had bought on eBay, and found something peculiar: My component tester indicated that these FETs (Field Effect Transistors) were actually showing as NPN type transistors (BJTs). (These are two very different parts!) To make a long story short, the FETs I bought on eBay were fakes! Someone had printed the part number of the more expensive FET parts onto a cheap regular transistor body, and sold them as FETs.

Here are some tips to avoid getting burned when buying semiconductors these days, in the age of chip (and semiconductor) shortages, and the resulting increase in scam artists using this as a way to make money.

Buy a component tester.

Buy an inexpensive component tester like this one on Amazon. (I don’t get paid for this suggestion). Or Google on “component tester,” and you will find dozens of options. Just get one! They mostly all do the same thing: You plug in a part, and it tells you what kind of part, and what the various values the part has. Here is a photo of a component tester showing a good JFET (Left) and one with the fake FET (Right).

If it’s too good to be true…

If some sellers on eBay are selling a semiconductor for $10 each, and you find a different seller selling the same item for 1/10 of the price: Be suspicious. Check the return policy to make sure you can get a refund. If you purchase a real bargain, be sure to check the parts as soon as they arrive. If they are fake, then immediately request a refund through eBay or Paypal before the return period is up.

Check the Photos

Let’s say you want to buy some 2SC1307 transistors. Google on “2SC1307 FAKE,” and you will see photos of legitimate versus fake 2SC1307 transistors, and other information on how to spot fakes. If the photos in the eBay ad match the photos of fakes, then steer clear.

These 2SC1307 transistors typically go for about $10 each. Before I was aware of the counterfeit parts scam, I ordered several of these for a really low price. I was going to use them for final output transistors for a linear amplifier that I’m building. It turns out that the transistors I received were bogus. They were functioning transistors, but when I put them in a circuit, they were only good up to about 5mHz, and not the 30mHz or higher that they should have had. They were fake. And after googling on “2SC1307 Fake,” I could see that my bogus transistors matched the photos on the known fakes.

Below is a photo from the web site https://dk7ih.de/fake-components-and-how-to-recognize-them/ which discusses fake parts. On the left is a “legit” 2SC1307, with the fake being on the right. The part on the right looks exactly like the “bargain” parts that I bought, and which turned out to be fake.

Not all cheap parts are scams…

I bought a bag of 1,000 2N2222 transistors for about $20. That’s a penny per transistor. And these parts work perfectly, and roughly match the specs of other 2N2222 transistors that I have bought elsewhere. But the 2N2222 is so plentiful, and has been made by many different manufacturers, so it’s plausible that this deal would be real. And I’ve used dozens of these with good results, so I feel confident that these parts are the real deal–or else they are such good fakes that it doesn’t matter.

Out of the six batches of bulk (i.e. more than quantity of 10 pieces) semiconductors that I have bought in the last 6 weeks, 2 out of 4 orders from eBay were fake (Fake FETs) and 1 out of 2 orders that I placed from Amazon were fakes. The orders that yielded good and cheap parts (FETs) were ones that had somewhat more obscure part numbers, like 2N5458, and BF245C. This suggests that the scammers are focusing on the most popular parts on the market.

Out of Spec Parts

Some parts sold on eBay and Ali Express, etc. may be legitimate parts, but way out of specification. For example, I bought several packages of 1,000 capacitors of different values on eBay, half expecting them to be junk. When I received the package from China, I tested a bunch of the parts. And while capacitors are commonly up to 10 or 20% different than their stated value, some of these bargain capacitors were more like 80% off! For example, one batch, the 100nF capacitors: actually measured as 55nF on the component tester. Another batch that were supposed to be 470pF, were actually: very close, at about 465pF. Sometimes ebay sellers will sell bulk parts that failed to meet manufacturing specs, but are still working parts.

Fortunately, there was very little variation within each bag of capacitors. The bag marked 100nF for example contained capacitors that were all approx 55nF. So I marked “55nF” on the bag, and used the parts according to the actual value shown by the Component Tester, and not by what was marked on the part itself. The capacitors worked fine–I just had to pay attention to the actual measured value of the capacitors.

Reputable Sources

If you need to be sure that you are getting non-fake parts, then you have the option of paying more, but almost certainly getting authentic parts. Some online sites that I have used and that are very reputable include digikey.com, mouser.com, and jameco.com. I have personally purchased many parts from each of these online stores, and never had a problem. There are many other reputable providers–these are just the ones that I personally have used. I had a positive experience when I bought some parts from Jameco. I only discovered a year later that half of the parts were wrong (not what I ordered). I sent one email to Jameco customer service, and that same day I was given a UPS overnight tracking number with the replacement parts, no questions asked. Now that was a good deal!

Radio Mnemonics

By: Elizabeth – KI7AUH (KI7AUH at arrl dot net)

Mnemonics, a memory device. When my mother made me take piano lessons I learned Every Good Boy Does Fine. (I don’t remember what it stands for). How about Left-y Loose-y, Right-y Tight-y. I still find this useful. You and I probably know many more of these we only remember when needed.

Power Pole Connectors

My latest favorite is for Anderson Powerpole connectors: Red Right/Tongue Top. I have borrowed a crimper from a neighbor and am making a whole bunch of wires with powerpoles on one end for future unanticipated needs. As I strip and crimp the wires I think to myself Red Right/Tongue Top and I feel smart and confident. Later (when I’ve returned the borrowed crimper) I can connect other things to the other ends.

I’m sure I know more of these mnemonics that I only remember when needed. (Antennas put up in bad weather have better reception doesn’t count). So must you. So when you’re in the middle of a project and one of these memory devices arises from the back of your mind…. Take note, finish the project, and then email me. I’m starting a list and I’ll post it here on this website (or on groups.io/g/jeffhamradio) and share with anyone who wants to know. We’ll all get smarter.

Preparedness: Lighting

Headlamp
Duracell headlamp #1600008

A headlamp can be your best friend when the chips are down and the lights are out in the field or at home.

I found this little jewel at COSTCO in Sequim, next to the Duracell Batteries, and sporting the Duracell brand. It uses 3 “AAA” batteries, either the standard alkaline or NiMH rechargables. It has 4 beam settings: (1.) dual spot/flood beam (500 lumens/2 hrs), (2.) low spot beam (50 lumens / 12 hrs), (3.) high flood beam, and (4.) night vision red beam.

What sets this headlamp apart from others is the quality of the high flood beam. To test it, I turned out the lights in my ham shack and sat in the normal operating position. The intensity was appropriate and comfortable, illuminating my entire field of vision. Due to the beam’s even distribution, I could look around, down at the desk or up at the clocks with the same ease as if the studio was fully illuminated. There was no need to consciously direct the beam. It would be easy to forget that I was using a headlamp–the light distribution was that good.

Though the light can be found on Costco’s website, it is only available through their warehouse stores. At under 20 bucks for 3 headlamps including batteries, this stocking stuffer could be a useful addition to any ham’s go kit.

73 everyone, Roger, KL7HI

(Link to Costco website: https://www.costco.com/duracell-500-lumen-led-headlamp-3-pack.product.100526264.html

October 2 Meeting & Presentation: Introduction to WebSDR

October Powerpoint
Click image to download PDF file

Regular Meeting Wed, Oct 2:

I guess we have all felt the cooler temperatures and some falling leaves. That means it is time for the club to have its annual election of officers. The slate needs to be announced at the October meeting and the election in November. If you want to run for any position, especially as a Director, let me or any Board member know before Tuesday at noon.

Our holiday potluck will be at the December meeting. We should be able to have both member donated and club funded door prizes.

I hope to do a program with a live demo of WebSDR if the internet link is working. I have some Power Point slides also. Since you only need a web browser, maybe someone has a hotspot I could use.

As always, if you have a show and tell, show up and tell everyone about it.


73, Dick Illman

Video

VECOM/DART Exercise at Jefferson County Airport

Jefferson County Airport Food Flight required coordination of several volunteer groups and agencies. See the food flight in action…

HamWAN for Jefferson County

John KX7JM adjusts position of the radio atop the Cape George Fire Station. Our link is near Victoria BC about 40 miles distant.

Hello all,

We successfully set up a 5.9 GHz HamWAN node at the Cape George Fire Station! Thanks to all who helped set things up. Dick, Chris, Randy, Ken, Gretchen and Roger all helped to assemble the dish, radio/modem, and roof mount for the node, and fabricate and run the exterior grade Cat5 cable that powers the radio and brings the ethernet signal down into the radio room. Continue reading