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1. The cable is good and ready for use.
2. The cable is open through the outer shield.
3. The cable is open through the center conductor.
4. The center conductor is shorted to the shield.
5. An intermittent condition exists that causes a short or open when the cable is flexed. 

1. Take one end of the disconnected coax.  Remember, we are NOT able to test continuity with the coax connected to any equipment or antennas. Touch one multimeter lead to the center pin of the PL-259 plug and the other to the outer metal part of the plug.  You should hear nothing, indicating that the cable is not shorted.  This is always the first test, because we must eliminate the possibility of shorts before we can make any assumptions about the center conductors or the shield.  
2. Next, take the clip lead and use it to short the coax at one end by connecting the center pin of one of the PL-259 connectors (it doesn’t matter which one) to the shield side of that same connector.  Take the free end of the coax and touch one multimeter probe to the center pin and the other to the metal shield of that PL-259.  You should now hear the buzzer that indicates continuity.  
3. You have now completed the basic tests, because you have determined that the cable is not shorted and by passing a current through the entire length of the center conductor and back through the shield, you have determined that both the center conductor and shield are intact.  The final test is to flex the cable and wiggle the connectors while performing both of these tests again.  If it helps, you can add two additional clip leads to connect  the multimeter probes so that you don’t have to try to hold them in contact with the PL connectors. This will help determine if the cable is intermittent.
4. If the cable fails any of the tests, feel free to test the shield to shield and center pin to center pin connections separately.  Never use a cable that is suspect, because it could cause damage to your equipment.  
5. Last but not to be missed is a final check along the length of the cable for any obvious bad spots, such as a break in the outer jacket or any suspicious bends or bumps in the cable.  

Pat Tice, WA0TDA, is the manager of HANDI-HAM and a regular contributor to AmateurRadio.com. Contact him at [email protected].

Yesterday the Medion computer speakers that I used with my Elecraft K3, failed. I was WSPRing on 10m and had the speakers switched off at the time but I saw some unusual interference on the waterfall and switched them on to listen. Nothing happened. No audio, nor did the blue power LED light up.

I checked the obvious things such as the cables and that the power supply was delivering 14V DC. It was. I took the speaker containing the audio amp over to the workbench and tried it on the bench power supply. Although the speaker was behaving as if no power was being applied, 20mA was being consumed when the switch was on. I have no idea where it was going.

Without a schematic there isn’t much I can do but I doubt that the speakers are repairable anyway. There are no active components on the circuit board apart from one integrated module attached to a small aluminium heatsink. This has presumably let its smoke out. There are a number of capacitors on the board and the cable connections are extremely well filtered against RFI. I have never seen such attention paid to preventing RFI. I guess that this is because Medion is a German company and Germany seems to be the only country that takes compliance with EMC standards seriously. The speakers were almost completely immune even when I ran 100W. Having a tone control they produced very rich-sounding audio from the K3, unlike its internal speaker which is shrill to listen to and has very little bass response.

I’ve now replaced the Medions with a pair of passive speakers that I originally got for this task but with those the audio sounds boxy no matter how I fiddle with the K3’s RX EQ settings. The only benefit of them is that I’m using one less wall wart!

These Genius speakers look like they might be a good replacement but ordering a pair would be a lottery as I have no way of knowing if they are RF-proof enough. One pair of Logitech speakers I bought were a dead loss. They were handed to the local Oxfam shop within an hour of the postman delivering them as they were so sensitive to RF they were beyond hope.

Julian Moss, G4ILO, is a regular contributor to AmateurRadio.com and writes from Cumbria, England. Contact him at [email protected].

I did a little updating on my FM VHF Operating Guide. Take a look.

Your feedback is appreciated.

73, Bob K0NR

Bob Witte, KØNR, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. Contact him at [email protected].

MakerShed announced a new product that will probably appeal to radio artisans who like to build little rigs.  It’s the Menta, a smaller version of the Arduino which fits nicely in the venerable Altoids tin.

Get a few 2N2222s, some toroids, resistors, and a crystal soldered on the prototyping area, then burn some CW keyer software on the Arduino and voila, you got a nice little QRP rig.

Work has been conspiring to eliminate my spare time but I was able to spend a few hours over the Easter holiday to clean up the shack and make space to put the Heathkit AT-1 on the desk again. I have been able to spend a little time going over parts that need to be replaced and making a list.

The Heathkit AT-1 chassis with case and VFO-1 behind.

There doesn’t seem to be any show stoppers although the wafer of the meter switch has broken in two and will need to be repaired. If I’m not able to repair it then thankfully it is fairly simple and replacement rotary switch can be substituted.

This isn’t going to be a museum quality restoration but the changes that were made to this transmitter in the past were sensible and if left in place are representative of period modifications. The original meter for example was not the highest quality and a Western or Simpson replacement would be an improvement. The original slide switches have been replaced with period snap-toggle switches which are also an improvement over the original.

The Heathkit VFO-1 however has been modified for grid-block keying which is a significant departure from the original and I plan to revert it back to cathode keying. Although a technical improvement it is not in keeping with the original design and needs to be undone. Everyone will have their own opinion but I think if I wanted modern circuits I’d get a more modern rig, so the VFO-1 will be returned to stock.

Hopefully I can carve out a bit of time here and there to work on this and slowly return it to working condition.

Owen Morgan, KF5CZO, is a regular contributor to AmateurRadio.com and writes from Texas, USA. Contact him at [email protected].

QRPometer complete

Well the QRPometer has made it from a pile of parts to a very useful tool for the shack and portable op's. It's no wonder this kit sold out in record time and now the 4 state QRP group will have to round up more parts and move out some more kits as the demand is out there. I began this project the same way I have with all my projects.... by doing a parts inventory. That went by without a hitch all the parts and pieces were present and accounted for. It was then off to the "puttin" the parts where they belong. The instructions are very easy to

Solder blob mod done

follow and very well laid out. If you are not sure about things and need a picture you will find it on the 4 State QRP groups website. During the resistor install there is a note to hold off on two resistors until after the calibration stage. I did get an email from the 4 State group letting me know that there is also a third resistor that should not be installed as well. Now that is great support each person that ordered a kit receive an email with updated info! There is a very small mod that has

Ribbon cable soldered to LCD

 to be done to the LED meter a solder blob has to be removed from a pair of pads. A new blob has to short a pair of center pads it went very smooth and allowed me to use my Hakko 808 to remove the solder blob. With all the parts installed it was now time for calibration and I wish all kits could be this easy to calibrate!!! All that is needed is a voltmeter (my Fluke meter) for the first step and then an RF input between .5W to 5 watts (my trusty K3) for this second step.


The kit pro's
1. Very easy to build and calibrate
2. No toroid or SMD for those kit builders who shy away from them.
3. Instructions are well written and very easy to understand.
4. Meter has a built in dummy load when measuring power.
5. When meter is turned off it can still be left in series with antenna and transmitter the meter is in bypass.
6. Professional silk screen front panel.
7. Parts layout on the the circuit board are...may I say "Elecraft quality"!

Con's

Calibration complete

1. The TX and ANT connectors are RCA and not BNC. I had to buy RCA to BNC adapters.
2. There is no cover for the back of the circuit board.

So lets put 2 and 2 together.......7 pro's to 2 con's = home run!!
Mike Weir, VE9KK, is a regular contributor to AmateurRadio.com and writes from New Brunswick, Canada. Contact him at [email protected].

As mentioned in the activation alert from last week, I attended a local amateur radio club meeting on Saturday morning and presented Summits On The Air (SOTA) to the club membership.  My presentation covers all aspects of both chasing as well as activating and I had available all my normal activation gear on hand.  There were approx. 25 members on-hand for the presentation and I would estimate by the amount of questions, that at least half (perhaps more) will become active chasers.

After the meeting and a brief lunch, six of the members accompanied me on the activation of Genesee Mountain.  Genesee Mountain is part of the Denver Parks and Recreational System.  It is a well maintained area with a paved road providing an easy walk about 90% of the way.   

The six other amateurs accompanying me wanted a nice leisurely first SOTA experience and that is exactly what I wanted to provide them.  The original plan was to drive all the way to the top, park and then hike down 100 vertical feet, then back up.  However, Genesee Mountain park road wasn’t open all the way the highest parking area.  The main parking area is less than 1 mile (0.8 to be exact) from the summit with an elevation gain of about 200 feet.   Everyone in the group felt comfortable with this hike and we took a nice easy stroll to the top.  I handled packing the communications equipment needed for the activation.

We reached the summit just before 2100 UTC (3 PM local) and quickly began setting up the Buddipole Versatee Vertical for 20m. I briefly explained the setup and began calling CQ at 2115 UTC.  Within just  a few minutes I had the first QSO in the log and we took turns working each station until everyone had their four (or more) QSO’s in the book. 

I (we) worked a total of 10 stations including N1EU, K7ASQ, K7ATN (S2S), WA2USA, ND9Q, KK1W, AD5A, WB9WHQ, K6ILM and W5DLD. 

In the above photo, KDØBIK (red shirt) helping NØHIO work his first SOTA activation.  I would like to thank NØHIO for providing the photo and video of the activation. 

Watch this video on YouTube.

I’m fairly certain those who participated in the activation will all perform their own activations in the near future.  I’m also hoping to get another SOTA activation planned in the next couple of weeks.  The KX3 should arrive (hopefully) in the next 2-3 weeks and of course I will need to test it out and the best way I know of doing that is Summits On The Air.

Until next time…

73 de KD0BIK

Jerry Taylor, KD0BIK, is a regular contributor to AmateurRadio.com and writes from Colorado, USA. He is the host of the Practical Amateur Radio Podcast. Contact him at [email protected].