I'm moving...

I'm in the process of moving my qth. I'll be back up and writing in a couple weeks.

Tube..

December 7
“A Date Which Will Live in Infamy”~ FDR

Today the Azalea Coast Amateur Radio Club in Wilmington, NC brought the U.S.S North Carolina to life on the airwaves. The U.S.S North Carolina calls Wilmington home, birthed along side downtown in the Cape River. The North Carolina BB-55, NI4BK(NIBK military designation) was the first vessel to enter Pearl Harbor after the attack December 7th 1941.

The ham radio operators including myself operated from 2 of the ships many radio rooms. We operate a modern Yaesu transceiver but utilize the ship's original wiring and antenna to broadcast our signal around the world. Some the contacts on SSB today include one Russian station, California, Texas, Vermont, Maine, Colorado, Wisconsin, Louisiana, and Tennessee to name just a few. One of which was a vet who was stationed in the Pacific during the war. We also made a QSO with the USS Kidd. Those QSO's, contacts, we're made on the 20 meter band.

NI4BK is the callsign of the ship as provided by the FCC, but it's original military designation was NIBK. I am proud to stay that for 1 and a half hours I brought the old girl online.

74xx Contest Prize

7400 Contest

These are terrible pictures but I wanted to get something up right away to show appreciation for my prize to the 7400 folks. Now what this is, is a device that takes the 20-pin connector from a computer power supply and give you used power points to run things. As you can see there's a Ground, 12v, 5v, 3v and a -12v points. There's LED's from each volt, a powered LED and a device on LED. Of course at the top right next to the 20-pin plug the push button, On/Off switch.

Tube Headphone Amp Project Update

Just a quick follow up entry to the Tube Headphone Amp project. I've received updates that my PCB's are back from the fabricator and are being processed. Specifically they are cutting down the master board into the individual orders and hopefully mine will be shipping out soon. I'm really rather excited about the project. Between getting married and this project, 2012 will end out with a hell of a bang for me. Just to specify, I did yes mention my fondness of marriage and this electronics project together. Picture this, your holding a 40 foot ladder and placing those two things on the ladder I can assure my fiancee, should you make it over to reading this post, the marriage is well up at 40 feet. My amp is probably rung number 4.

Anyways check back often. The second the boards come in, I'm assembling and hopefully remembering to take pictures.

Last Project of the Year-Tube Headphone Amp

This is just a little write up for you all of what I think will be my last project of the year. This one was an easy one. I did very little work on it. Mostly just a few modifications of a previous design and when everything arrives, assembly. Now as I said, not my original design this time, but that's ok. It's a epic design none-the-less.

What is it you ask? A Tube Driven Headphone Amplifier. Link below.
http://diyaudioprojects.com/Solid/12AU7-IRF510-LM317-Headamp/
Specifically it is a 12AU7(ECC82) Tube / IRF510 MOSFET Headphone Amplifier.

It uses one 12AU7 vacuum tube for signal amplification and a pile of other great passive components and a few semi-conductors.

So far I'm not very far into it. I have ordered all my parts. As of Sunday November 25th I have received:

1. Groove Tubes ST-12AU7 Preamp Tube Silver - Link
2. 9-Pin Tube Socket Ceramic PC Mount - Link

Printed Circuit Board - PCB

In addition to all that I've also out-sourced my PCB construction to a pretty awesome service. Which is called OSH Park. These guys, best I can tell, round up multiple orders for PCB's and submit them as one board to there builders. This makes it worth while money wise and your not stuck with 50 copies of one board. This is what has forced me in the past to make my own PCB's. Which I hate to do!

With this service you create your circuit board in Eagle CAD and then upload your design to there website. It will ensure a proper design and tell you how much your going to be charged. It also renders you out pretty pictures of basically how your board will look. I included mine below. Now when you order, you have to order in multiples of 3, but that beats 50 or more. I paid $21 USD for my project. Which to me, that's not bad. I've got 3 boards coming, that's 7 bucks a piece. I can sell 2 of them if need be to pay for the entire project easily.

Click to Enlarge

Click to Enlarge

I'll keep you all update on this. I'm a big audiophile and am very much looking forward to completely this project!

Second Operating Positon

Following my experience from Field Day 2012 I've been thinking. What can I do? I did help as much as I could with setup and operating, but I did not really contribute anything. So between now and the ARRL 2013 Field Day I'm trying to get things together. Being I am now a General Class operator with plenty of operating privileges I will be acquiring a HF capable transceiver. I've also recently gotten a mobile dual band rig. As written about previously.

What I did today was wire in a second operating position in my SUV. Version one of what I did was to simply run 2 CAT6 cables from the radio mounted area to the back of the SUV and crimped on RJ-45 connectors. I then used f-f couplers to hook everything together. This worked just fine, but had 2 flopping cables in the back. You know, flopping around. Well that was version one.


Version 2 is a little more buttoned up. I've maintained the same cables running to the back from the radio. Now, instead of 2 RJ-45 connectors at the end of these two cables, there are two keystone sockets. One to plug microphone and one for the control head. This way the look i cleaner and a little more flexible interface. To house all this I picked up a slim electrical box. I put some 3M Velcro strips to hold it in place. And finally I simply mounted my keystones in a 6 port face plate. See the keystones you buy with various sockets and plugs are a universal square snap in fit.

Why go through the trouble you ask? Well as I mentioned I'm doing this in preparation for Field Day. I imagine myself sitting in a chair working my radios from the car. This is so I can go flip the two cables and plug up to setup a station in the back. That simple. I don't have to un-mount the radio, find power in the back, plug everything in and then be on the air. 1 minute and I'm going. I would love to find some switching device that would let me jump back and forth without having to go to the radio and switch cables.

What do I have left? Well not much if I'm honest. Directly for this project I need audio in the back. 2 speakers. Specifically the MFJ 281 ClearTone Speaker. What I'm planning on doing is fabbing up a bracket to mount the speaker right inside the SUV to the roof. I'll setup an audio switch of some kind to send it to the back and I'll have either 1/8 jack keystones or hard wire it up.

7400 Competition Entry-Signal Strobe

This is my entry for the 7400 Competition. This a signaling strobe, an enhanced one with a siren. My device is built off of 7400 NAND Quad Gate, 2x 7476 J/K Flip Flop, 7432 OR Quad Gate and 4x 555 Timers. Now off course there's a few passive components like capacitors, resistor, 5 volt regulator, LEDS and several switches. All built on one large breadboard, but I believe this could be fabricated on a 2x4 PCB, maybe smaller

To be able to complete the project for the 7400 competition I wasn't able to find locally the I/R diodes or the high output LEDs that will mentioned later. I will good over it POU, point of use, and a bill of material will be included at the very bottom.

Instructions

Using the master on/off switch either applies power to the circuit or removes it using the single-pole single-throw switch. After turning on, the strobe portion of the circuit has 3 conditions: A). Visible light strobe, B). Infrared spectrum strobe or C). both Visible and I/R together. This can be done one of two ways; by switching each light condition separately with the appropriate switch or, by using the switch marked both to activate both light conditions together. Once activated, the strobe lights, which are LED diodes, act in a “X” crossing pattern (wig-wag). The frequency in which the lights jump back and forth can be adjusted using the potentiometers, one for each diode type.

In a secondary circuit, powered by main 5 volt source, is a 3 watt siren circuit, similar to the American police siren. Just like the strobe portion, once the master power switch is activated, the siren is switched separately from the strobes to allow for selectable times of use. To activate the emergency siren simply depress the only push button switch on the device. There is selectivity to the siren too. By rotating the beige knob counter clockwise you can take the siren from a whooping sound to a high-pitched scream.

To return the device to the ready position turn the siren off, place the toggle switches for the strobe functions in the up position (towards to the top) and flip the master power to off.

Point Of Use(POU)

As the title describes, this device was intended to be used in Search and Rescue, Military, and any situations in which signaling from the ground to air is needed. This circuit utilizes 5 watt white LEDs as primary signaling illumination, with a 3 watt blue LED used as part of the alternating pattern. Secondary to the signaling illumination is a strobe pattern that includes 3 watt IR LEDs and one blue low power LED. The white LEDs provide upwards of 200 lumens, which has a usable viewing distance of approximately 250-300 yards. Using condition one of the strobe device it enables the white/blue strobe. Using three 5W LEDs and one 3W blue LED provides hundreds of feet of usable viewing bandwidth. White is used to stand out against most any terrain and one blue is used as a depth of field or contrast color. This depth of field and distance would be difficult to see if you were just using one color especially since blue is the hardest color on the human eye to view. This viewing difficulty allows for the greatest long distance impact in operating conditions.

As mentioned, there are two conditions to this device; the visible light strobe and the secondary Infrared strobe. Used in conjunction with night vision goggles, which amplify light (including a portion of the IR light spectrum), IR strobe can be a very useful tool. In night vision goggles, (NVGs) IR light does not diffuse as rapidly as white strobe would, especially in hazing or rainy conditions. Aerial operations, specifically in non-military S&R, typically work in the 400 - 750 ft of altitude range. This, as discussed above, is right in the sweet spot for the visible light white strobe and a more than safe range for IR. Just like the white strobe, the IR setup works in a crossing ‘X’ pattern. Two IR diodes flash and the next goes, which in this case includes one IR and one blue low power LED. Once again, this will give a good depth of field to the spotter.

 

Bill of Materials

Part used:

LED’s 2 - 5W White 3 - 1W Blue 3 - 3W I/R Diodes	4 - 555 Timers	1 - 9 volt battery and caddy	5 - Single Pole Double Throw Switches	1 - LM7805CT 5v Regulator
1 - 7400 2-Input NAND Gates	2 - 1k Ω Pots	4 - 150 Ω resistors	1 - 2.2k Ω resistor	1 - 8 Ω speaker
3 - 1 Cap	1 - 7432 2-Input OR Gates	2 - 7476 Dual J-K Flip-Flops	2 - 100 μF Cap	1 - .1 μF Cap
1 - 1m Ω Pot	3 - 10k Ω resistors	2 - 1k Ω 1% resistors

Kenwood TM-V71A Dual Band: Installation in Dodge Nitro, Continued Part 3 - Mounting and Assembly

Figure 6

Figure 5

What I decided to do. The remote control head would be velcro-ed the a ledge on the dash. This ledge is slightly angled so that the display is angled upward for best viewing. I also have it rotated ever so slightly to even further improve the viewing angle.(Figure5 & 6)

Next, where to mount the body of the radio? What I came up with is under the front passenger seat, towards the back. With the contours in the floor pan and the rear bench seat the way it is, this is really, I think my best option. One day if I feel adventurous I may mount it under that bench, but not today.

Kenwood TM-V71A Dual Band: Installation in Dodge Nitro, Continued Part 2 - Disassembly

To continue with with my previous post about my mobile installation of my Kenwood TM-V71A dualband. So we are done figuring out the logistics of actually setup up the remote head. Now on to my method of mounting.

As mentioned I'm driving a Dodge Nitro SUV. I initially thought that this mobile install was going to be a pain. Actually it's not remotely difficult. Getting power into the cabin from the battery is super easy, opening up the dash is super easy, as is the center console and mounting both parts is easy.

Figure 2

Looking at the image to the left, figure 2, you see a picture of a Dodge Nitro dash. With the battery of the SUV being on the left side, drivers side, that is where I focused my efforts in wiring.

Looking at the image to the left, figure 2, you see the speedo cluster, the knee panel, radio area and center console.