Monday, February 20, 2023

The New Shack

The new shack is coming along.  A major milestone was reached -- heat in the new "shack" -- essentially the garage off the house.  My old shack was a separate building and I hated having to walk back and forth carrying coffee or in the dark or in the weather.

By moving the shack right off the connected garage (now that it is heated), I can still operate without disturbing the YL and be close enough to get a fresh cup of coffee and a snack while operating.

Plus the new shack will have a better layout and more room.  The old shack will be converted into storage.

It has me re-thinking my antennas too.   The "Sky Loop" will need to be fed differently (partial window line, partial coax, with a 9:1 Balun - not too excited about using a balun in the feed, but I was using one anyway with the Palstar (Kessler) AT-AUTO.   At least the balun in the feed will be a stouter and better design than the Palstar balun (according to sources).

Too many projects now --

Re-do the shop/shack.

Then work on a new portable antenna for the up-coming field day and other trips I plan to make.

I am trying to devise a new "Jumbo-Buddi-Pole" knock-off and see if it can be made from the surplus aluminum I can find here.

I like the overall design of the Buddi-Pole in terms of conversion for different bands.  I might copy the design a bit but make it taller and be able to offer easier hookup for tapping the coils.

When I go to Visalia, I'll be stopping by in Los Angeles first to see some family and check on a very dear friend who inspired me to go into ham radio.

But check-list marked -- the heater is installed and throwing out "50,000" BTU of heat into a space that will be a new electronics workshop and ham radio shack.   I am looking forward to that.


Thursday, February 16, 2023

Planning for Visalia

It's not right around the corner, but April is just 6 weeks away for Visalia.  I'm getting anxious about the convention and looking forward to seeing and hearing new things about DX.

I'm going to be using a vehicle and driving to Visalia.  The "Van" will have solar power capabilities so I will be able to operate my portable radio from the campground while in town.  I am very interested in getting the Van setup to allow routing the coaxial cable from inside to outside.

Debating if I want to use the Buddi-pole antenna or find some other way to mount a vertical near the campsite in Visalia.  I have a surplus of aluminum tubing and I am curious about building a jumbo sized "buddi-pole" that will let me run a cubical quad (get the thing high enough is the challenge since the shape of the quad is bulky)

The experiment on this trip will let me know what kind of configuration will work when I attempt to work remotely for some upcoming contests or events that involve rare grid squares in Washington State.


Tuesday, February 14, 2023

Northwest Ten Meter Net

So the NTMN CW Net kicked off LAST Tuesday, which means I missed it, but tonight we had the CW net right on the dot, 7:30 Local Time (Pacific).

Jim, K7NCG was NCS and we had two check-ins.  Myself and Al, KB7TBC.

Al was a bit low in the noise but his signal was weak to me, which is not that unusual for 10 meters in the northwest especially when I am trying the copy the stations up near the county line in Snohomish/Woodinville area.

It was a real fun thing to do and I hope we can attract more amateurs in the area (or abroad?) to join is.  Jim really knows a good way to keep the flow going and straight forward.  Easy to copy too.   After the net we QSY to our SSB frequency and just go over any small details as education for how to do better next time.

At this rate, we'll need to order hoodies and baseball hats.

Stacking Cards

Trying to get a handle on the DX QSL situation.    I knew I had about 40 or so cards from ATNO laying around in the shack in boxes and I finally got them all sorted out.  Had to look up the "procedure" from ARRL to get them in proper order so I can have them counted.

Just crossing off the new countries that I need to work but also now trying to work on per band DXCC numbers.   I think I can probably finish off 30 meters soon and 10 meters may not be that far behind the way the solar cycle is running.

40 meters is close too.   I think the 15 meter total could use some work.   20 meters is over 200-210 or so and that means it's just down to the Islands and Difficult Situations (let's leave it there).

I need a system though -- a way to organize the QSL easier.

I did send off my request for FT8WW, which was confirmed in LOTW but some nice wall paper would be a welcome addition to the shack.


Tuesday, February 7, 2023

Like Riding a Bike

Isn't that what they say?  Getting back to CW and making contacts.   The flow is starting to come back to me a bit and I'm able to copy pretty reliably but it will still take a lot of practice to be able to copy some of the faster CW from DX.   

Never was a rag-chew operator so if the CW gets into detailed stories and dialog I just get swamped, but the key things (pun not intended) will stick out well and I'll copy that.

30 meters has just been brilliant for a long time, and the stations that work CW there have been relatively strong too.

I'm reading more and more about amateurs who are eschewing the QRO station power and going QRP with great results.   That's a multiple benefit situation since it takes less power and equipment to operate with the after-burner 3-500Z.  If I can swing bare-foot, that would be great!


Saturday, February 4, 2023

SWR for Solid State Linear - Question

This next question is more abstract.  I hope you can help me unravel the puzzle.

Before I tackle the big QRO solid state linear, I'm building a smaller solid state linear.

Let's assume one of these MOSFETs:   IRFZ24PBF    In later designs for QRO, I'm going to get one of the monster NXP power MOSFETs.  But, before the QRO, I want to establish some framework to test, hence the point of the question below.

Now for the setup:




Let's think abstractly. 

Suppose I have two "devices" (home brew etc.)

One is a "SWR detector".  It is a device with two inputs and one output.
The two inputs are RF_IN_SENS, and RF_OUT_SENS
The one output is N_TX_ENABLE

When the "SWR detector" (analog circuit) examines the RF_IN_SENS and RF_OUT_SENS it will pull N_TX_ENABLE (active low) when the SWR exceeds a redline (a redline designed in the SWR detector).

When RF_IN_SENS compared to RF_OUT_SENS reveal a SWR within limits, N_TX_ENABLE is pulled high.  It's an active low signal.

Push that aside.

Next the the other device is "RF Amplifier"  and reduced to simple terminals has:
TWO Inputs:   KEY_DOWN  and RF_IN
THREE outputs:  RF_IN_SENS, and RF_OUT_SENS, RF_OUT.

Assume that the amplifier samples the input and output for the benefit of some external equipment, The SWR Detector.    Hence RF_IN_SENS, RF_OUT_SENS -- those are samples of the actual signals.
The raw signal from the exciter is given to RF_IN, and the raw amplified RF is delivered by RF_OUT.

Here's the question:

Suppose the SWR detector pulls N_TX_ENABLE low (it finds bad SWR), active low.

I do not know if I should:

  1. Trigger that the RF_OUT is attenuated to a low power -- this keeps the "bad SWR" present, but lowers the RF_OUT so that while the SWR is bad, adjustments can be made (safe for the finals) to alleviate the bad SWR.
  2. OR, trigger that the RF_OUT is shunted off to a perfect load to protect the finals while the SWR can be fixed.

The problem I have is if I choose #2, I lose the actual bad SWR (even if RF_OUT is attenuated) to know when the Detector has been satisfied.

If I choose #1, I lose the opportunity to 100% protect the finals from any bad SWR, but I lose also the actual bad SWR condition to know if I've corrected the problem.

Eg, in other words, if the SWR detection exceeds the redline my instinct is to let the Amplifier see the bad SWR, but just attenuate it sufficiently to protect the finals while the tune on the antenna load can be adjusted. 

Attenuate or cut off completely?

I assume also that it's right to attenuate the RF_OUT, not RF_IN while the redline condition is detected.

I'm asking this because when I build the small-scale (60W SS linear) I want to build up a test-framework that I will want to use when I pivot to build a bigger SS Linear.

If this doesn't make sense OR you're too busy to entertain, that's fine.   Let me know and I'll ponder it more.   Worst case scenario is I melt some transistors.

Comments this question are welcome.

Remember, it is in the abstract.


Friday, February 3, 2023

New Shack

For a very long time I used my detached workshop as the "Shack".  It was 100 feet away from the house and although it has heat and power, it is a hike (and I don't like having to walk back and forth between the house in the dark -- when chasing DX at night, a refill of the coffee Thermos).

Also, given that the heir-apparent is no longer living with us, we have a collection of stuff in the garage that I'd like to relocate.

An idea came to me that I have this all swapped.   I'm going to revise the Garage and make it the workshop and then move all of the boxes and stuff to the old Shop.  This means making a new "Shack" and that gives me some opportunities.

It will let me re-build a bench and electronics work-area.  It'll be heated and it will be connected to the house so I don't have to stumble around in the dark when I am up past 2am working DX.

The only glitch is that in order to re-route the antenna feeds, I will need to be creative because there are some gardening/shrubs and other things I don''t want to disturb.

But if I can resolve the feed-line routing and the existing antennas can still be reached via the feedlines I have access to, this should work.

Put another way, when I started out in ham radio, I had practically no equipment so the "Yaesu Map of the World" was easy to mount and see from the operating station.  With all the gear I've collected over the years and in use, the gear is now making it difficult to operate -- too much gear in too dense a location.  This new "Shack" plan will alleviate that.

When I get to that point, I'll post!

But the goal is to do the shuffling of boxes/stuff from one place to the other.

LotW Upkeep

I made the mistake of not keeping my Log Book of the World certificate updated.

The upgrade of Log4OM logging software sort of fouled up my LotW cert (not sure exactly what happend since the LotW cert had not yet expired yet Log4OM  or TQSL was confused about the actual cert to use.

In any case I had to re-cert myself.  

"Don't let this happen to you!"

Check your TQSL.  Make sure you have an active Cert.

WHILE you have an ACTIVE cert you can update it.  Once it's expired, you cannot.







Things happening

It has been a busy few months since I hung up my software-spurs. On deck -- DX'pedition for Lord Howe Island Lord Howe Island (July 202...