Category Archives: K9ZW Operations

PMing Your Radio

After writing my Quiet Word about FlexRadio I realized it has been some time since my main Flex-6700 had any serious preventative maintenance (PM).

Recently I has sent my RiserBond TDR off to be PM’ed and recalibrated.  I have had a fellow ham do PMs on all mu Collins S-Line gear.

So why do I not have my other gear on a schedule for PM?

What should that PM schedule look like?  Based on hour powered up, hours on the air, the raw passage of time, or?

Most of us pull a PM when something isn’t working correctly or breaks down.

At that point if the problem is with the gear we are maintaining it is not really PM, rather break-down response, and if the gear that broke down is actually something else we find ourselves doing PM influenced by another gear problem rather than the actual unit we would be PMing.

So I have broken down my gear’s PM schedule into:

FlexRadio/4o3a and Solid State Gear, if in active use:

  • User level PM annually
  • Bench Grade PM at three year intervals

FlexRadio/4o3a and Solid State Gear, if NOT in active use:

  • User PM annually if openly stored/prepositioned
  • No user PM requirement if in sealed storage

Tube Gear if in active use:

  • User and professional PM per the manufacturer’s recommendation (user level at least annually)

Tube Gear if NOT in active use:

  • User PM annually if openly stored/prepositioned
  • No user PM requirement if in sealed storage and the gear is fully updated
  • PM prior to return to service if in sealed storage and NOT fully updated

Cables/Incidentals (only if in use as part of the station):

  • Inspection/PM annually.

Anything Outside:

  • An additional inspection and seasonal maintenance pre-winter and post winter

Anything to be Sold:

  • A pre-listing inspection and PM, including run-up if appropriate

Not certain if I will make specific inspection and PM notes for each major unit , or let common sense guide the PMs.  Hmmm….



An Unusual QSL Batch

August 1st 2022 DX QSL card haul (was four envelopes)

The NIDXA W9 bureau (Northern Illinois DX Association) is awesome and fairly regularly I will get one their brown NIDXA envelopes with another batch of inbound QSL cards. (Link to NIDXA is

Each envelope contains roughly 10-11 cards, an amount sized to best manage the postal costs.

Every now and then I might get two of these brown NIDXA envelopes in a given day, or back to back on successive days.

Monday August 1st (2022) my inbound mail was unusual, as there were Four NIDXA envelopes!  Each had the typical 10-11 cards in them!  Woo Hoo!

The breakdown by country was:

  • 5 cards from Holland
  • 1 card from Belgium
  • 3 cards from the Ukraine
  • 5 cards from Japan
  • 29 cards from Germany

Quite a nice batch of QSL cards.

Other than replying to direct QSL cards received, I haven’t done a bulk DX QSL card print since well before the pandemic.

For my DX outbound I had been using GlobalQSL but they seemed to have shut shop during the pandemic.  I haven’t been able to find out the backstory, but with the modest credit I had with GlobalQSL I also depended on them for reference on to what date I had QSLed up to in my logs.

Once I figure out what date to start from and filter out domestic QSOs, I will to find a new service.

One that I am trying out is the Spanish QDure service – as they seem ready to handle the many thousand DX cards in arrears that I want to catch up on.  I’ve done 15,000 QSL cards as a trial order with QDure and will see how this works out.  As it turns out they will do Domestic QSLs for me as well.  Kind of curious how that works out, but it is worth the try!

Looking for any other suggestions where I can download my QSO data and have cards printed and sent to bureaus?



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Back on the Air after 12 days of Covid Virus

“Thank you!” to Vincent KX4SR for the 20m FT8 QSO that marked my return to the airwaves after a 12 day absence due to Covid.

When back on July 15th after a 20m QSO with Joseph KF0EIR I shut down, I didn’t expect it would be 1-1/2 weeks before I would be back on the air.

While I could have remoted into my station while in isolation, I really wasn’t up to it. SSB/Phone wasn’t in the cards given the deep cough and sore throat combined with sleeping most of the time. Doing FT8 when awake would have been possible, but I was motivated with a focus on getting well.

It is good to get back on the air, even if it will be just digital mode for a few more days until the random coughing episodes abate.



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Handling the Voltage Multiplier Issues with High Line Voltage and Vintage Radios

What is “normal” household line voltage?

What is acceptable to our Vintage Radios?

Without getting into a deep discussion the voltage delivered to the average American home has gone up since the pre-WWII’s 110vac, then post-war 117vac is now 120vac.

The current standards are:

Yet our old radios might be intended for less.

My two Collin’s S-Line Stations definitely were intended for a bit lower voltage than 120vac.

Inside the S-Line components voltage can be multiplied to produce Vacuum Tube level voltages by step-up transformers.

If the original design took say 110vac and upped it to 800vac, it is a 7.273 multiplier.  (The 800vac is just a value I picked, as there are several stepped-up voltages in use in a S-Line station.)

If modern power is suddenly say the maximum allowable of 120vac  plus 6% for 127.2vac, the 7.273 step-up transformer is pushing out 925vac, which may be above the maximum safe voltage for a particular application.  Even a 120vac line voltage will he 873vac after the step-up.

What the Collins designer originally really wanted was that 800vac voltage they designed for, which would mean we have to figure out a way to limit the line voltage to 110vac.

Well you cannot call up your power company, as ask them to “turn my voltage down for me, guys” That isn’t going to get you anywhere.

Here is the solution:

Actually what is in those boxes are these:

Medium Duty Variac Transformers where we can “dial down” the output voltage to that ideal 110vac area.

The capacity (2KVA) is sized to handle a 516F2 power supply and 30L1 amp, and the build quality is solid enough to do shack duty with ease.

I bought these from an eBay seller, though the identical units were also available on Amazon, with the 16% Amazon cut added to them of course.

Each S-Line setup is getting its own unit.  The third is for other projects.



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Lending a Helping Hand – W9EMY’S First HF QSO

Spending the long Memorial Day weekend on Washington Island (WI-001L) Wisconsin, I learned that Emmett W9EMY had taking his Tech & General tests together, applied for a vanity call as he was sequentially assigned a tongue-twister call, BUT hadn’t made an Amateur Radio contact!

One of his Elmers, George W9EVT seemed to have presumed that Emmett W9EMY had his station on the air, and like true gentlemen they “talked around” what could have been a question of “Hey W9EMY, how about knocking out some QSOs?”

Emmett had asked to look at my ZeroFive Flagpole Vertical Antenna, and when I asked him if he had his station running and how did he like making contacts, I learned he hadn’t been on the air.

Well that sure needed to be fixed!  So tuning the Island QTH Flex-6700 across 20 meters, we heard Rick VE6CQ holding court, working stations at a good pace.  So we listened and talked about the parts of the QSOs until a nice opportunity came up to have W9EMY call VE6CQ.

Turns out I had the microphone gain too hot, as I had switched to a Neuman mic on a boom for Emmett to us, but left the settings for another mic.  Rick VE6CQ came back with additional information that our settings were messed up.  My mistake fixed in less time that it takes to type about it.

Emmett W9EMY and Rick VE6CQ had a great classic QSO with VE6CQ throwing in an on-air pep-talk about amateur radio, HF and I think he may have worked in an appreciation of life itself in there somewhere.  I was inspired by Rick VE6CQ’s pep-talk even though I was the Elmer rather than the new guy that day!!

Time restraints kept Emmett’s first foray limited to that first QSO, but I did do a quick FT8 demo as Emmett wanted to see that in operation.

Then we arranged a Sked (scheduled contact) for the following day, and Emmett W9EMY from his home Flex-6400 station had a roundtable discussion with myself on my Flex-6700 and George W9EVT who was on his Kenwood TS-990S.

Now that we were all within a small local circle kind of made it easy,!  Actually W9EVT and I are a fifteen minute walk apart, and Emmett is another twenty minutes or so further west than George W9EVT is  from my QTH.

Was fantastic to get another new ham on HF for their first contact!

And to hear Rick VE6CQ’s pep talk was icing on the cake.



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Slowly building one’s Logbook

K9ZW LoTW April 2022

It takes a while to build up the QSOs and QSLs in one’s logs.  Seems that of the QSOs I upload to LoTW about 58% end up being confirmed by other LoTW users, becoming LoTW-Qualified QSOs.

I’m understanding that percentage is a fairly typical result.

At my present weekly QSO rate, I am expecting to cross the 40-thousand QSO mark later in August 2022.