Monday, November 12, 2012

OT: Science Project

This is way off topic, but I wanted to share a science project that I made with my 12 year old daughter last year for her 6th grade natural science class.  She was required to make a replica of a cell, whether animal or vegetable didn't matter, as long as it was accurate and labeled the components that make up a typical cell.

We decided that we wanted something that was a little more impressive than your run-of-the-mill school project made with noodles and play-dough.  So after much brainstorming and looking around hobby stores and Home Depot, we decided to go high-tech.

We constructed the cell walls out of plexiglass:
We made a cube out of six pieces of plexi, then build two spacers for inside the cube out of four more pieces.

Connected the pieces of plexi with clear packing tape:
We make sure to keep wrinkles to a minimum and used just enough tape to keep it together.

Added organelles by printing them on 8.5" x 11" labels:
We cut the shapes out using an Xacto hobby knife to be able to keep close to the lines. 

And gave it a little flash with a Sylvania LED "Light Flute":
This was a little tricky.  The hardest part was positioning it close enough to door to be able to turn it on, but not so close as to have it turn on by itself or break the plexi.  I tried cutting a hole in a sheet of plexi for the switch, but ended up breaking it, so we just pushed it up next to the "door" and left it like that.

The final result came out pretty well!  Here are a few pics of how it turned out.

With the lights in the room on:

And again with the lights off! 

We used clear labels to label the individual organelles.  This was a really fun project!  The teacher liked it so much that she kept it!!  It is on permanent display in her class room.  This is not a ham project, but it was still a lot of fun and I wanted to share.  Hopefully it gives you some ideas to use yourself.


Richard, KK4JDO

Wednesday, November 7, 2012

Mobile mounts

I just got my new mounts in today for the radios that I built the console for in the last post!  I've been trying to figure out how to mount the antennas for my radios in such a way that they work good and look good.

When I only had a single radio in the truck I used a Comet hood-lip mount with matching coax connector.  This mount works okay, but it is a bit bulky.  I have never been a fan of lip mounts as they sometimes deform the surface that they are attached to.  This one seems to be large enough to spread the stress out over a fair area and may alleviate this issue.  I haven't seen any deformation in the six months that I've had it on.  Here is a pic of the truck with this mount using a 38" Diamond 2m/70cm half-wave antenna.

As I said, this mount seems to work pretty well. But I wanted to add a second or third antenna without starting to look like a four-poster bed.  So I decided to investigate stake-pocket mounts to relocate this antenna and add the additional antenna for the CB in the other stake pocket.  After much searching and reading I decided to order some mounts from Breedlove Mounts out of Gastonia, NC.  They had amazing reviews and seemed like a good deal.  I ordered the EZN Flat mount Model #14 (SO-239) and the Model #55 (3/8" stud) mounts.

I ordered these mounts Sunday evening off of their website, and the arrived with today's mail (Wednesday).  Pretty quick service!  The mounts appear to be extremely well made.  The craftsmanship is top notch and you definitely get your money's worth.  Here are a few pics, front and back, of the mounts that I ordered:

As you can see, these are extremely well made and rugged.  The only thing that I would suggest is adding some anti-seize compound to the screws.  This should keep the stainless steel screws from possibly spalling in the aluminum mount over time.

So once I moved the Diamond antenna from the front to the back and installed the Hustler FG-27S I was completely happy with the results.  The mounts were strong and stable, as well as providing a good grounding solution that is drilled and tapped into the bottom of the bracket.

This turned into more of a review than a project, but I hope that you've found it informative.  In an upcoming post I'll cover the coax runs and the DC grounding.  I need to do some additional grounding for the radios, as well as under the truck to try to quite it down electrically.


Richard, KK4JDO

Tuesday, November 6, 2012

Mobile Install

I drive a 2011 Ford F-150, which is not the most radio friendly of vehicles.  It's not the worst, but it is not the best either.  When I only had a single radio in the truck, it was fairly easy to accomplish a professional looking installation.  As I added an 11m radio, and then a scanner, things got more difficult.  I ended up deciding that I needed to build a console in place to house these additional radios.

Yaesu FT-2900R

The first radio that I put into the truck was a Yaesu FT-2900R, which is a 2m mono-band ham radio.  This F-150 has a cubby hole at the bottom of the dash under the climate controls, which fit this radio like a glove while conveniently allowing plenty of air circulation to help cool this 75W solid aluminium beast.  I took out the cubby hole section, removed the back of it with a dremel, mounted the radio inside, and *bam*, it looked like original equipment (of course, that was before this blog, so no pictures).  The only downside was that it was a little difficult to see the top of the display on the FT-2900R to see if the offsets and tones were on at a glance.  This worked fine and dandy for months...

Galaxy DX-959

Enter a Galaxy DX-959 CB radio (if you're a ham and hate on CB'ers, keep it to yourself, I like to be able to talk to the truckers while making long trips, and sometimes it's just fun).  There is a world of difference between the way that a lot of CBs are built, versus the way that a lot of ham radios are built.  First off, they tend to be bulkier and flashier.  Needless to say, this wasn't going to fit in some handy preexisting pocket...

Radio Shack PRO-2050

Then along comes a scanner that I had originally purchased for use inside, then got into the whole scanner thing and decided that I wanted more features available in the house.  This makes for an interesting mounting challenge since there are no built-in mounting options on this scanner!  This brings us back to the whole idea of building a console for this all to fit into.

I decided that if I built a console, it would need to house all three radios, not just the two additions.  It would also need to look as stock as possible.  And lastly, it needed to be cheap!  I have seen some awesome custom professional installs but I have also seen some amazing price tags on them.  Since I'm not on an episode of "Pimp My Ride", I had to have an affordable solution.  I went through several iterations of the design, with the biggest issues being how to physically mount the radios in a small location.  My final solution was to build a box that fit between the vertical trim pieces on the dash, and angle back to the seat.  Originally, the radios were to be flush mounted, but to better make use of space I ended up angling the radios inside the new box.  Additionally, the original though was to have the box be independent of radios so that I could remove them individually for service.  However, space constraints dictated otherwise.

The end result was achieved by mocking up the sides of the box using cardboard to create a template, which was then cleaned up and copied to 11/32" plywood.  Once this was done, I was able to start finalizing the placement of the radios that I had mocked up earlier on the cardboard.  I ended up connecting the Galaxy radio directly to the plywood due to the space constraints mentioned earlier.  So much for a modular design.  

Since the scanner and the Galaxy radios were of similar size, they became the top and bottom spacers for the console.  I then used some scrap 1"x 2" to secure the two pieces of plywood together front and rear.  I used some scrap plywood to build a set of rails to hold the scanner in place, since it doesn't have a mobile mounting option.  The Yaesu presented a problem, since it was over two inches narrower than the other radios!  I ended up building spacers out of the 1" x 2", and mounting the 2m radio to them.

I then bought two $5 black rugs from Wal-Mart that closely resembled the carpet in my truck, and used a combination of 3M spray adhesive and carpet tacks to cover the sides of this contraction that I was putting together.  

Once all this was done, I had to take the whole thing apart to install it into the truck.  That turned out to be a pain in the rear!  Things that line up easily on the bench sometimes don't work so well in real life.  Such was the case with this console.  No tweaking was needed, but maneuvering around in the confines of the pick-up when I'm decidedly in the fat-boy club was a challenge indeed!  After much cussing and ill-will, things finally lined up properly and I was able to see my handy work:

As you can see, the radios are held securely, but it definitely needed a top!  This became in interesting problem.  How to come up with something that would fit?  Measuring would have been a major pain and I always mess that up anyway.  So back to the cardboard!  A snip here and a snip there, crumble it up, start over, and eventually, poof, a template is born!  I then transferred that to some 1/4" plywood that I had laying around and got busy with the jigsaw.  Eventually (and a few broken parts later) I had a top for the console!

But that's ugly, who wants to look at wood all day in a pickup?  So how to finish it?  I could paint it, but that would look funky.  I could stain it, but again, wood...  So I decided to cover it in vinyl.  A local upholstery shop was nice enough to give me enough material to take care of it, after declining to do it for me (they were afraid of breaking it, which I understand since I broke a few).  Again, the dilemma, how to actually do it?  The final decision was to use the spray adhesive again, and just razor blade the holes for the radios.  It actually turned out pretty well!  The only downside was that the end-grain was exposed, but a handy sharpie marker took care of that...LOL!

The finished product turned out like this:

Please no comments about the state of the dirt on my floorboard.  Consider it an experiment to see how long carpet survives without cleaning!

If I had it to do over again, I would try to cut the holes a little straighter with the jigsaw, and I would probably use some flat bar stock and build cradles for the radios to allow them to be serviced individually without massive effort and potentially marriage shattering language.

I'll attach a few more pictures, just because I can, and I am proud of this lash-up for some reason.  ;-)

Eventually, I intend to add an Icom IC-7000 to the mix.  I'm not sure whether I'll replace the Yaesu with it, or if I'll keep it so that I can monitor 2m or run APRS from the truck.  What do you think I should do?  Anyhow, if you've made it this far, you should be ready for bed, your insomnia has been cured!


Richard, KK4JDO

Saturday, November 3, 2012

Quarter Wave Ground-Plane Scanner Antenna (and 2m ham antenna)

One of the purchases that I got via eBay is a Radio Shack PRO-2050 police/fire/etc scanner.  I've never had a scanner before, and this was a cheap way to check it out.  I didn't get a pick of it before I ended up moving it from the shack to the truck, so I nabbed a picture of the internet.  Here is what my scanner looks like for those that haven't seen one:

Of course, since I had a scanner, I needed an antenna.  I'm just getting into the whole scanner thing, so I didn't want to spend too much on the antenna since I didn't pay much for the scanner (which is several years old).  One of the cheapest and easiest antennas to build is the quarter-wave ground plane.  I had some #8 ground wire laying around, as well as an SO-239 connector, so I was off to the races.

There are several good calculators out there to help get the proper dimensions, however, the math is fairly simple:

468 divided by Frequency in MHz gives you the half-wave element length in feet.
The quotient from above divided by 2 gives you the quarter-wave element length in feet.
Take the quotient from the last problem and multiply it by 12, the product is the length of element in inches.

For example, if you want an antenna for the middle of the 2m ham band: 

(468/146) / 2 x 12 = 19.23" which roughly equals 19 1/4" (since tape measures are in fractions of an inch).

It helps if you cut it a little long to allow you to tune to your specific location.  I actually cut mine for resonance on the public services band (~150MHz) since that is what is in use in my area, however, I get acceptable performance on the 2m band as well (about 1.7:1 VSWR).

Bending the ground plane elements down to 45 degrees brings the resistance of the antenna closer to 50 Ohms.  I'm not sure how this works exactly, maybe someone could drop a post and let me know why this works.

Here is a quick pic of the completed antenna.  The ground plane elements sag a bit with they are supporting the weight of the antenna.  They are straight when the antenna is suspended properly.

I also added vertical stubs for the 440MHz band as well as the 800MHz bands.  I didn't add ground plane elements for them as I'm not sure that I would see any benefit from doing so since I have the 2m elements.  Here is a close up of the verticals.

The last thing that I did was to seal the top of the connector with some silicone caulking.  This will help to keep water out of the coax, which would degrade the metal over time.  I would have used coax-seal, but I ran out and didn't feel like spending the money on this antenna.

And the final thing that I need to do, as you can tell from the background of the picture above, is clean my work bench!  It is getting crazy in there, so hopefully I can get that squared away soon.

My Parts List:

  • 1 x SO-239 connector
  • 8' of #8 grounding wire
  • 4 x little screws
  • Caulking
Time to Completion:
  • About one hour for this one, mainly getting the jig built to solder the pieces together.

Next time I'll work on getting better pictures.  I tend to feel my way through some of these projects and don't think to document as I fumble along.


Richard, KK4JDO

And... We're back...

To anyone that cares, sorry that I haven't posted in such a long  time.  My real job as a systems engineer at a children's hospital can get hectic at times.  On the bright side, we successfully opened a brand new, absolutely state of the art hospital in Orlando, FL.  Check it out at >here<

In addition to working some completely insane hours, I also moved from the massively over-sized house in the burbs to a marginally under-sized house in the country.  I'm into RC planes as well as Amateur Radio, so having a place with a lot more land allows me to enjoy both of my hobbies at home.  It also helps that this place is cheaper to heat and cool being that it is around 1,200 sq ft smaller that the last house.  Hopefully we'll be able to buy again in a few years.

I have had time for a few projects, mostly in the last week to two, and I have had some searches running on eBay and a few other sites (like  As a result of these searches I have been able to acquire a Kenwood TR-9500 that I really wanted, as well as the matching BO-9A base and matching PS-20 power supply.  All that is left to have a complete system is the SP-120 speaker.  These occasionally show up on various sites, so I'll keep my eye peeled for it.  Here is a neat quick pic of my new rig:

The TR-9000 is on the middle shelf, left side (red freq display), and the TR-9500 is on the right side of the same shelf (green freq display).

Both of these rigs are all mode radios, so I have the ability to use single side band (SSB) in addition to CW and both narrow and wide band FM.  This is handy as some of the older satellites use SSB.  It also allows me to start dabbling in the world of VHF/UHF weak signal work, which takes place on SSB as well.  It is kind of neat to see how far you can talk on what are usually local area bands.  I am waiting on a Mirage B-108 to show up, which is an 80W amplifier that also contains a receive pre-amp to help with working low strength contacts.  One of these days I want to check out EME, or "moon-bounce", but that requires some seriously high-gain antenna arrays or even dishes (like re-tasked old satellite TV dishs, the big Ka band ones, not the little 18" DirecTV trashcan lids).

I also built a couple of quick desks since I no longer have an office.  I had to turn my "ham-shack" into a "ham-corner".  I built two identical desks out of 3/4" plywood and 1x12 whiteboard.  The main goal was to use as much vertical space as possible to maximize my storage options.  They are not quite finished yet, I still need to add trim, and build the linking section to make is a complete corner desk instead of two stand-alone desks.  Be at least I have a place to put my radios.  Here is a quick pic of the desk with my ham gear on it.  The other desk contains the gear that I use for work and is just to the left of it.  Not that anyone really cares how my shack is set I thought that someone might be interested in how my desk is designed.  Post a comment if you would like to see actual plans for them.  ;-)

One of the things that I am considering adding to the desks are a set of doors to hide the equipment when not in use.  I'm using the corner of my bedroom, and while I'm okay with seeing my stuff all the time, my XYL is only marginally impressed with the whole ham radio out in the open concept.  ;-)

Anyhow, I have a few other projects that I've been working on, and will work on adding those in additional posts this evening and in my "spare" time.  For now, have a good evening!


Richard, KK4JDO