The POTA PERformer Antenna

After my trip to Vanuatu, I wanted to work on a portable antenna with a few requirements.

1. Require less horizontal space to setup than my 80m-10m MFJ-1982MP End Fed-Half-Wave antenna (EFHW).

2. Quicker and to deploy that the MFJ-1982MP

3. No Tall structures required

The EFHW has about 133 feet of radiating wire and needs a fairly tall structure and over 100 feet of horizontal length. This is normally mitigated by pulling it side ways towards trees to give it a "zig-zag" pattern coming down. However that only seems to shorted the run-out space by about 20-30% at the must.

Deploying this antenna can be done in as little at 330 minutes, provided I find a a decent enough tree, and I sling the throw bag and rope around the target branch on the first throw. I don't have the best of records, however, this hasn't happened often. The longest it has taken was over and hour that is just too long.

Some parks just don’t have a decent trees to support the dumb-end of the antenna or I am not able to sling a rope up to a good branch. I do carry a 20ft painter pole on the roof, but I would like to eliminate that too. Also, while I have not had any bad experiences with park rangers or officials, I'm sure that I am doing a better part, not breaking branches trying to get an antenna in a tree.

Enter the POTA Performer. Please watch Michael's video . Link: This antenna does not have 80m but is good on 40m and Up. The parts can all be aquired farley easily.

Below is the list of parts I used.

- Tripod or other 52 inch mast. Greg (the designer) used a 40-inch piece of furniture-grade PCV pipe, a stake and threaded coupling.

- Insulating plates for my tripod. I designed a set and is available on Thingiverse Link

- (4) 1/4-20 x 2 inch long stainless bolts from Lowes item 396457

- Chameleon CHA SS17 17’ telescoping whip from HRO. Their house brand OPEK is $10 less link.

- Procomm JBC-995 Mirror Mount

- Generic Red wire 18AWG from Walmart item 1172297

- Borrowed RF Choke (I need to purchase my own)

- 20 pairs of 1/4 inch spade terminals

- Terminal Crimper (I don’t have a good one. no link to provide) - (4) 1/4" ring terminals from NAPA auto parts. (no link to provide)

- (2) 8-inch zip ties

- 8 inches of generic trimmer line. (Used to crate the band link isolator)

- (2) 48 inch Electric fence post from Tractor Supply Link. (I used purcple so it would be more visible)

Optional items

- Generic Blue 5mm shrink tube. (I used this to differentiate the two radials

- 5mm Shrink tube for Epson label printer(I used this to label each radial link for what band it is used on

- Generic corkscrew Dog tie-out. (Used to stabilize the tripod when the radials are pulling in their respective directions)

- (5) feet of generic para cord. (Used to stabilize the tripod when the radials pulling in their respective directions)

Chart of Results. I performed these tests twice in my backyard. Once with the antenna mirror mount connected directly to the neck of the tripod, and once with 3D Printed insulting plates. Below are the both sets of results.

Table of test Results

. With tomorrow being Veterans day, I plan to take this to at-least one or two parks to see how well it does with the current propagation. I hope this sparks your interest in this antenna. If you have any questions dont hesitate to reach out to me, or you can ask Greg Mihran, KJ6ER directly. Both of our email address are good on QRZ. 73 Savo - K2SAV

Motorola Radius Bracket

The bracket that is included with the Motorola Radius and Maxtrac line of radios is called a Trunnion. When these radios an handled off and sold on sites like eBay, the bracket and/or bracket screws tend to go missing. You can obtain thes at a minimal cost to replace them. The thread is M5 x 12mm long. A standard 10-32 screw will technically work. However M5 is the correct size. You can order these from Motorola Dealer or you can use any ordinary M5 screw. Motolra supplied mouting screws are nice make tightening the radio down effortless with no tools required. I have found that these M5 thumbscrews are a more economical alterative and can found at the Amazon link below.

20-Piece M5 Thumbscrews Threaded Knurled Thumbscrew Grip Knobs Thumb Screw for Machinery Latche with Storage Case (M5 x10)¡­

These thumb screws are only 27c each and don't have to be sourced from a special location. If you are in need of a tunnion bracket, I have found one on Thingivese that gets the job done and worked for me for a short while. I even printed off a few copies to provide to others. Stand for Motorola GM Series I have recently attempted to replicate the orininal trunion bracket for these radios in TinkerCAD. The link to that model is below. https://www.thingiverse.com/thing:6187420. The model is still a work-in-progress but is comming along quite nicely. It even includes the detents to help lock the radio into the roational position.

Casontimer HT1-257h 24Hour conversion

Model Clock: HT1-257H
IC:

how: what needs to be done: For this model clock. There is a jumper for 24hour mode.  All that is required is to reflow the solder and install a 10mm long jumper wire as shown below.

  

IC/PCB graphic

Pic 12HR  Pic 24HR

More Mods

Lens for Digital Clock - 7 segment display diffuser
Display Intensity: I would like to at a switch,variable resistor or photo resistor to limit the brightness of the display.

Datasheet:

http://pdf1.alldatasheet.com/datasheet-pdf/view/205672/HOLTEK/HT48R30A-1/+Q0W78WV.MKTGLdlZz./1wvllD+/datasheet.pdf

MM 5387aa - WesClox

IC:MM5387AA-N
how: Short pin 38 to VSS(Ground)

 

In this Westclox example, pin 38 is the 24Hour SELECT pin.  The next pin, 37 shows that it is connected to Vss (ground) when using a multimeter.  The pin-out diagram shows this as having no connection. I have tested this with a jumper wire from pin 38 to the solder pad on pin 37.   This resulted in the display switching from reading 5:27pm to 17:28, as shown in the following examples.

Note that you could flow some solder from Pin 37 to 38.  This would "permanently" switch the clock to 24 hour mode.  I have no issue with this, but for the sake of convenience to "normals",  perhaps you could jumper this to a new switch mounted in the back of the clock cabinet. This would allow the next user(s) to select between either 12 hour or 24 hour mode.

Provision for more switches

Based on the datasheet of this IC, it looks like this alarm clock could be further modified with two additional switches. Perhaps even a double throw switch as these two features would not be used simultaneously .  This model clock does not make use of a SECONDS display.  I could install a momentary switch to Vss (ground) that would display the seconds of the current time.  This might be useful when attempting to synchronize this clock with another.  This is on pin 32

Also, another switch to Vss (or the other throw of the same switch), would show and enable SLEEP time if this clock were utilized in a clock-radio device.  This is on pin 30. However, if you are going to take take advantage of this, consider what you would use it for.  It is intended to trigger a relay when enabled. This relay powers on a radio circuit and subsequently turns off this same relay after a specific amount of minutes (SLEEP). The SLEEP trigger is pin 30, the output is on pin 27.  Also, consider Figure 6.  This indicates to me that the SLEEP enable switch not only connects pin 30 to VSS, it must also break the connection for OUTPUT COMMON SOURCE. This would be pin 23

Display Intensity

To Be Added

Datasheet:
http://pdf1.alldatasheet.com/datasheet-pdf/view/9252/NSC/MM5387AA.html

Floss interview about ZFS

Oracle podcast on ZFS

Welcome to the Show

Hello all, Welcome to my brain.

Ever find your-self wishing that you could see in to the mind of someone else?

Did you ever want to know what other what others seem to understand in their sleep?

This is all for you.

This is my tech blog. I plan to discus technology. Review computer products from newegg.com since all the other retail establishments are all utterly useless. At least, until I get a Seist and Desist order from the lawyers from the City of Industry.

Everyone is welcome to comment. There will be plenty of ranting and ravings.

Speaking of crappy places to buy technology that will only last 6 months.

CircuitCity They sell electronics right?

I thought so too. Well apparently it is the place to go if one thinks that product breadth is the psychological equivalent to a computer with no internet connection.

I went there with my girlfriend to get a new Bluetooth ear peace. I was greeted with a mute dummy that was no better then a cardboard cutout of a person.

All he could do was point me to the Verizon Wireless kiosk in the middle of the store.
You know if I wanted to purchase overprice telephones accessories, I would go to the actual Verizon Wireless Corporate Stores located in any major mall.
Not this stupid redundant kiosk.

Tell me. Anyone have this same experience of going to giant national electronics chain only to be given same number options as going to a $5 Barber shop?