Thursday, January 17, 2019

What a FUN project!!!!!

Okay, so here it is under construction:


Ran Technology 4 channel oscillator board

What a neat little project!  First a little background.  I have some ham friends that go to the big hamfest in Friedrichshafen and also to Dayton.  I always make the same requests:

1. please find me another 70cm yagi antenna for 430 to 440
2. I need more crystals, especially 14.*** mhz and 7.*** mhz, 

Every year I get the same answer:  Sorry, didn't see any crystals there.

Now, I know that I can take a higher frequency crystal and grind it down to the frequency I need; my friend 4x1zz took a short seminar on how to do this correctly and he even has a crystal frequency oscillator reader that he built in Dayton.

HOWEVER, I still don't have the crystals I need to cover all of the 20m CW portion with my homebrew transmitters.  So what's a frustrated tinkerer to do?

Well, the folks at https://hayseedhamfest.com are selling for only $16.50, a 4-channel oscillator board.  What's great about this?  Well for one thing, you can plug in 4 oscillator chips available from Digi-key for about $5 each.  You tell Digi-key which frequencies you want on your chips, and then you plug them in.  That gives you 4 frequencies on the board.

I'm so excited about this that I can't wait to plug it into my 5 watt transmitter and be able to cover the 20m band from 14.000 to 14.070 just by choosing one of my four crystal oscillator chip channels.

And here is the chip itself:


The 4 pin oscillator from Digi-key

This oscillator chip has 4 pins.  It plugs into an 8-pin dip (off which there are 4 on the board).  The above chip is set permanently at 14.030.  My rig will tune about 14.030 down to 14.015 using this chip.  That is 15 khz of coverage with a $5 chip.  There are four pin through holes on the board, so you will have to clip off the 4 inner pins from the dip socket to make it fit.

CLICK HERE to see the Digi-key part.

My board is just now under construction.  Looks like the whole board will take about 30 to 45 minutes to build.  So as soon as I get it up and running, I will let y'all know how this really neat board functions as a replacement for actual crystals. Like these:



If the 4 channel board works as expected, then there will be no more searching for a certain crystal, all you have to do is just use a switch to click from crystal A B C or D in the frequency range you need.


The completed board without the chips installed

So stay-tuned and I will let you know how it does.

73

Mark 4x1ks

Monday, January 14, 2019

Now is the winter of our discontent...

I always wanted to find a way to put Shakespeare into my blog.  Indeed winter is here, wind and rain and all of that.



Of course in the USA, there are places where towers are covered with ice and antennas are drooping from the weight.  Here in Israel, at my QTH, there has been an abundance of rain this year.  The wind that accompanies the rain is not really welcome by me since I can hear the wind rumble through my tower; that just makes me nervous.

Which brings me to the subject of securing those guy wires and other antenna / tower restraints.  Lately I have seen some videos of some incredibly poor practices when it comes to erecting towers and masts.  It is absolutely true that you cannot defy the laws of physics.

The good news is that most hams are not shy about going to experts when it comes to tower raising and guy wires.  However, be sure to re-visit your tower situation as time passes to make sure that your guys and tower structure is still solid.

As a boat owner, I had old shrouds (shrouds are the cables that "guy" the mast) that were long due for replacement.  In many locations, insurance companies won't cover a sailboat unless the shrouds are replaced after a number of years (like 7 years or so).  The cables that are used may look just fine, and chances are they might be great for 15 years, but if they break, then the mast will fall, and a lot of bad things could happen.

The guys on your tower also endure stress, although not nearly as much as the shrouds on a sailboat, but the shrouds on a boat are built to take it.  I guess the point is to go out there and check those guy wires and also check the hardware that is anchoring those guys.  Replace whatever needs to be replaced, and NEVER go without temporary guys if you are replacing an old cable.

As far as winter goes, antennas can suffer a lot.  Back when I lived in Memphis, we had an ice storm that was just unreal.  My Cushcraft 4 element tribander was covered with ice and bent like a drawn bow.  It survived.  Try to buy the toughest antennas you can afford to stand up to the elements.


Will these elements survive the elements?

Speaking of antennas, if your SWR suffers when it is soaking wet out there, well you are not alone. Water can screw up antennas.  Usually when they dry out then everything is okay.  Coax and your connections is a real weakspot however.  If water gets into the jacket of your coax, then you will have corrosion and a poor performing transmission line.  Make sure that water cannot get into your coax.

Two weeks ago, I had a crazy SWR.  I went up the tower after a storm and discovered that the shield of my coax that was connected to one side of my driven element was corroded to being useless...even though it was still attached to the terminal on the element.  This was a connection that I made only 2 years ago.  Water and wind had done the job and corroded the braided wires of the coax shield to being non-conductive.  I cut away the bad wires and reworked the connection to the driven element.  The SWR is now just fine. 

In the winter when you see that SWR go up, then it can be water or corrosion.  Don't get too bent out of shape, but go up on that tower using appropriate safety procedures and fix those connections or even replace bad coax. Your SWR will come back to normal and you will be putting that RF where it should be...into your driven element.

Finally, operating in winter presents some challenges. Rain, ice, snow...not really the ham's best friends, but they can be endured and overcome.  For me, having a good heater in the shack is really my main focus on operating during the winter.  If I am toasty in the shack, then even if conditions are not ideal for DX, I can still sit and work on whatever project is sitting on the workbench.  So perhaps for winter this year, it is a good idea to have a project as a back up plan for when things are not working due to weather.


A Collins PTO rebuild...a worthy indoor winter project

It may be winter, possibly even to your discontent, but you can lighten that mood by building something in the shack in the event of soggy or frozen conditions outside your window.

So how are your antennas and/or tower(s) holding up this winter?  I hope just fine.

73

Mark 4x1ks






Sunday, January 6, 2019

This post is about the Eagles vs. Ham Radio

Ok gang, it's Sunday.  Tonight the defending Superbowl Champs (from my hometown of Philadelphia) are playing the Bears in Chicago.



So here's the dilemma: 

Do I get on the radio and enjoy some friendly CW chats on 40m OR do I watch the game.

First of all, watching the game is tense and occasionally disconcerting thing to do.  The SuperBowl last year was one of the most tension filled things I've done in the last 10 years.  Fortunately, it worked out ok....better than okay.

Working CW on 40m is mostly relaxing.  Of course,there are those clowns out there who just can't seem to get it through their heads when you send them "C" after they QRL?...that means go away.

So what's a Ham Radio operator to do?  Torn between two equally passionate opportunities.

I'm taking a survey right now.

1) Watch the Eagles beat the Bears, or get on the radio

2) What is your biggest conflict when it comes to Radio or ______________ (fill in the blank).

Love to hear your thoughts.

73

Mark 4x1ks

Friday, January 4, 2019

Don't give up on Peanut just yet....

Looks like some new life has been breathed into Peanut.

You can download version 1.43 for your android phone.

It appears that PA7LIM is getting some help with the site and the Peanut system.

More to come...

73

Mark 4x1ks

Wednesday, January 2, 2019

Say Goodbye to your legume friends

Well, the announcement was a bit of a shock, but after just a short life, Peanut is shutting down.

For those of you who do not know what a Peanut is, well it is a legume used to making a smooth or crunchy snack food.  It is also the invention of PA7LIM, David, who put together a clever little application that many found to be awesome.

Essentially, Peanut (the application software for Android phones), connected users to D-star and also custom chat reflectors without requiring the ham to buy a D-Star radio. Here is a link to the website.


The Peanut Android Phone Application Screenshot

Once registered, the licensed ham could connect to a number of XRF reflectors also with REF 030C and language-based reflectors like Korean, Swedish, etc. The convenience and ease of use was astounding, and that also led to a "social" problem.

A friend of mine thinks that the quality of the ham operators is inversely related to the ease of entry into the particular mode.  What that means is that the biggest lids in ham radio are attracted to awesome little apps like Peanut because they can get in for free.  In fact, REF030C was disconnected from Peanut fairly quickly after some turkeys abused their status as licensed hams and proceeded to behave like "turkeys" on the air using Peanut.  Shortly thereafter, D-Star shut down the connection from Peanut to REF030C.

However, the other sites remained active, and they worked very well. The audio is excellent, and although it is not what I consider to be "real" ham radio, nevertheless, it is a chance to talk to your friends using D-star without the cost.

According to David, PA7LIM, the creative genius behind Peanut, he no longer has the time to manage and code changes in Peanut due to the fact that his family is not getting the attention they deserve and need.  Therefore, he will rightly choose to shutdown Peanut in few days in order to spend more time with his family.  A proper decision.

Now that Peanut is about to shutdown, we can ask ourselves, what can we do to ensure that projects like Peanut survive.  At last word, something like 5000 plus users had registered for Peanut.  That is a lot of users to sign up in such a short period of time.  In my opinion, Peanut should be an app with a price tag.  A brand new D-star radio is going to cost a good chunk of change. So why not charge the user a $3 a year fee to register with Peanut.

Charging a fee would kill two birds with one stone.  The first is that it would allow PA7LIM to justify the time working on the project and coding.  The second is that many of the "lids" who treated Peanut and D-Star like CB radio will avoid Peanut because of the $3 fee.

Ham radio operators are some of the most talented and creative people out there.  Not all hams, but a significant number are 1st-rate technicians, coders, and engineers.  In the future, I think that we should consider supporting projects like Peanut with a few bucks to make sure that good products will stay alive and provide a great service.  Let's keep that in mind when the next "Peanut" project shows up.

73  Mark 4x1ks

Thursday, December 27, 2018

Ham Radio is not dead.

Here we go again.

Posted on March 26, 2018, was an article called "The Reality of Amateur Radio 2018." The article was penned by Chris G7DDN.  Here is the link to the article.

Here are some quotes from the article:

"The reality though for perhaps the majority of Hams on a day-to-day basis in 2018 is not so rosy."

The author goes on to describe how for most hams live with so much man-made interference that they live with constant S9 or above S9 noise on some bands.

"Then we have the Home Owner Associations coupled with the newer restrictive covenants that stop us putting up antennas, whether it be an 80 metre long wire or a 60 foot high tower. We have neighbours complaining about eyesores and about interference from “that Radio Ham” up the road."

Or this quote:

"Then we struggle with the fact that we are perceived, rightly or wrongly, as being old-fashioned, fuddy-duddy and out-of-touch."

The author does go on to seem to make an argument for the acceptance of internet-based ham radio as the possible salvation for hams that are faced with difficult antenna rules and local interfering noise.

So let's talk about that.

I do not believe that life for the "majority" of hams is not good.  I do believe that we make choices and decisions that are trade-offs based on our life circumstances.  For example, the XYL wants to live in a certain neighborhood.  That neighborhood may have lot sizes that are not conducive to putting up an 80 foot tower.  So we make trade-offs.  We find other HF antennas that will work with what we have, or we make the decision to NOT move into that neighborhood.  Decisions are usually based on compromise, especially when it comes to family, and most hams have family to consider.

That does not make the majority of hams SAD.  It is a choice to accept what is available, or to change your circumstances.

In my case, I have room for an 80/40 inverted vee (shortened on 80), and a 4 element tri-band yagi, and a vertical.  Not too bad, and I also have satellite gear and antennas.  Is this ideal?  No, not by any means is it my dream station, however, it works and I also get to live in the neighborhood that I like.  Of course, I told the XYL that when we move, it will be to a place where conditions will be more ideal.  A place with room for a 160m antenna and maybe a taller tower or even two.  That is also a choice.

Let me skip to the third quote above wherein we hams are considered old-fashioned "fuddy-duddy and out-of-touch."  To quote Clark Gable, "frankly my dear, I don't give a damn."

There is no way in H**L that I am going to care whether some guy who has the technical knowledge of a gnat cares whether the guy down the street is a nerd.  Nerds rule.  Therefore, I do not consider morse code or talking on HF to be old-fashioned at all.  I do consider these pursuits as manifestations of excellence in classic communications.  To make an analogy, should we ditch Mozart and Mendelssohn for 2018 hip-hop music because the classics are "fuddy-duddy?"  Yeah, well I don't think so.  Hip - hop makes me want to pull my ears off.

Being apologetic for practicing a magnificent art called amateur radio is just dumb.

The idea that homeowners associations are impinging on our hobby is absolutely true.  However, I have the freedom of not moving into that place.  Like I mentioned above, hams need to prioritize, and I want my freedom to put up whatever antenna I want.

Finally, embracing internet-based radio is a lovely idea, but it isn't ham radio in my opinion. Here's why.  Radio is by definition WIRELESS.  Don't get me wrong; as I write this it is somewhat lightning and thunder here in Israel, and I have my HF stuff unplugged.  So to get on D-star or Allstar or DMR is a nice alternative to HF on a day like today...but it isn't wireless communications.  I don't keep a log of my D-star contacts unless I met someone interesting and I will maybe want to contact him by email in the future to make a sked to work him on HF or VHF, or UHF, or Satellite.

The thing is, I don't want my amateur radio to be dependent on an infrastructure that is run by Google or Oracle or whoever else is responsible for the backbone of the internet.  If I have to, I can run my rigs off a battery and talk to my ham friends in the UK or Japan or the USA with no strings attached.

We hams need to preserve that because it is who we are and where we come from.  The internet is a plaything, but wireless ham radio is the real deal.

73   Mark 4x1ks


Thursday, December 20, 2018

Hit me with your best shot baby...

Sunspots got  you down?  Having trouble being heard?  Feeling inadequate?

That can happen when you are running your little QRP rig, even if you have a good antenna.  However, there may be a cheap fix that will put some "boots" to your mini signal.

Introducing a tiny little amplifier that will pump up your QRP transmitter like Arnold working you out at the gym.


70 watt amplifier parts

Check out the parts all laid out.   You have two unidentified final transistors (they have their faces buffed off), transformers waiting to be wound, 2 SMA connectors for your input and output, and the advertisement that this amp will put out a maximum of 70w.  The cost of this amp?  About $17.  That's correct, if this claim of 70w holds true, then you will take your QRP transmitter and make that little mouse ROAR.

So the proof is in the pudding, and this amp kit which I just received in the mail is still just parts in the bag, however, there are some youtube videos of these amps built and putting out power, albeit, not the 70w that is advertised, but still, significant power.

Think about it this way, my Ten Tec Century 21 "novice" rig has an input of 70 w max.  Output power is about 40 watts due to the fact that I recently swapped out the old monster capacitor for a new one.  That 40 watts from the Century 21 is plenty to be heard.


Ten Tec Century 21 70 watt input transceiver 

The issue with using the amplifier above as an add-on to a QRP transceiver is the need for a relay circuit.  You need to key the amplifier BEFORE you start pushing RF out of your QRP transceiver.  As I mentioned in a previous blog, with my 140 watt amplifier (AN-762), I built a 2 relay (SPDT) to switch the amp prior to the RF hitting the amp from the exciter (in that case the exciter is an Elecraft K2).

So now you have your two options for an exciter.  1) a QRP  Transmitter which will allow you to switch on the amp the old fashioned way with a TX / RX manual switch  or 2) using a T/R circuit like the Versa T-R mentioned in a recent blog here.

Which do you choose?  Well that depends on your skill level and your desire for a "commercial" style rig.  There is NOTHING wrong with using a manual TR switch.  You will use a DPDT switch to switch over the input and output of the amplifier as needed between transmitting and receiving.

Hams have been doing that for 100 years, and it works just fine.

What is the point of adding this amplifier, or any amplifier to your QRP rig?  The answer is self-evident in that sometimes that 4 or 5 watts just ain't gonna get the job done.  In about 6 or 8 years from now, you will be working the world on 1 watt, but right now we have what we have.

In the next few days or weeks, I will be building the little Chinese (claimed) 70 watt amplifier.  When it is ready, then this blog will give you an opinion as to whether the amp is able to really get the job done, and if it has a clean output.

KEEP IN MIND, with this kind of power output, you must provide a 5 or 7 element low-pass filter for each band that you are going to work.  There will be some losses, but they won't be detrimental.

If you are interested in buying this $17 amplifier, then look on ebay and/or aliexpress, and you will be able to search around for one with free shipping as well.

One last and very important thing is that you must provide a heatsink to keep from cooking your final transistors.  There are appropriately-sized heatsinks on aliexpress.  You MUST use heatsink compound to create a thermal bond between the transistors and the heat sink.  The heat sink will need to be big enough to do the job.


Completed 70w amp with aluminum heatsink

The aluminum heatsink will need to be about 50mm x 100mm...maybe a touch larger, and should be fairly thick with cooling fins as seen in the picture below.


A 100mm x 50mm aluminum heat sink is more than adequate

The bias voltage needs to be set for 2.7 v.  This will be discussed in a later blog.

There is no real limit on how pretty you can make your little amplifier look.  You can add nice lettering on the faceplate of a custom cabinet along with a volt/ammeter.  The sky is the limit in terms of how fancy you want your finished product to be.

So that is it for now, next step:  building it.

73, Mark 4x1ks