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!

Ham Radio Project-Tram Dual Band Antenna Rehab

It's been a while since I've updated, which is unfortunate. I enjoy my forum here. For today though I'm stuck at work, so I've brought my newest toy with me. It's a Tram dual band, 2 meter & 440, base station antenna. It was an eBay find I acquired for a grand total of $28USD.
So, with the help of a friend and fellow ham operator, NI4SR, I have made sure that my propagates well across both bands.

So here's what I've done or am planning to do today.
1.) I've already, carefully, removed the sealant/glue applied by the previous owner. I then re-applied some white Stampede "hardcore" caulk/sealant around the none-moving joint. Taking special note to precisely caulk around the base.
2.) Then I let that dry for about two hours or at least tack up. It's not fully dry yet.
3.) Then I very lightly scuff sanded, with fine grit paper, the fiberglass body of the antenna. Just to promote adhesion.
4.) After that I wiped it down with a damp cloth to clean and get the dust off.
5.) Then I applied my first coat of flat white spray.
5b.) The bottom half of the antenna has absolutely no moving parts, so it got a few coats.
5c.) The top half does slide into the bottom and has bushings so it only get two coats.
6.) Re-assemble!

This is not a hard project and my $100 antenna that I got for $28 will look like, once again, a $100 antenna.

Finished Project 1	Finished Project 2
Finished Project 3	Finished Project 4

North Carolina Maker Faire

Review of: The 2012 Charlotte Hamfest & ARRL Roanoke Division Convention

One of the things since I passed the Technician I've most been looking forward to is going to my first Ham Fest, licensed. I've been to HamFests before, more than a couple but less than several. I've been to the Huntsville Hamfest multiple times and possibly MemFest a couple. But either way I was looking forward to it. Well my dream came true, today March 10th 2012 was the Charlotte Hamfest in Concord, NC. I got up extra early this morning travel to it from Wilmington, 4 hours and I was there. I went to this by myself but hope to drag the fiance to one sometime. I tell you, I walked in bought my ticket went through admission area and looked forward and I was like wow. I was a little overwhelmed, but in a good way. I guess it's different when you are taking it in by yourself and this time I understand most everything I see in front of me.

I proceeded to the flea market first. If your not familiar with a HamFest all the ones I've been to have manufactures and large ham stores in an area, then kind of small business like name plates, shirt, small antenna builders in the next section of the arena. And then segregated together, normally either to one side or the back, is the flea market. And the flea is one word "everything." Seriously, there are resellers of hard components, connectors, electronics gear, radios, tubes(there's always at least one person with 4 tables of vacuum tubes), old computer, cameras, and anything you as a consumer of electronics might be interested in or previously owned. I bought a good set of alligator clips and odds and ends connector. Specifically I got a set of SO-239 panel mount connecters with a very thick flange. Those will go to an antenna project.

Long story short. The Charlotte Hamfest 2012 was a very nice hamfest and I had a very nice time. They had great programs planned(I caught most of a D-Star program), nice flea market, and great vendors area. It was in a comfortable heated and cooled arena. It was very well accessible to get into and parking. And was very well attended. I was also told it appeared that attendance was up which is great! I look forward to it next year!

Here's some pics I stole from MFJ's Facebook, props to MFJ for these:

Basic.........Basic...Basic..Power Supply

Got a few spare parts lying around, yeah me too. So I was playing around in Multi-sim, which is the coolest software ever, and came up with this slimmed down power supply. It will give you 13.7 volts DC from wall outlet/mains. It's not a perfectly clean circuit, with a clean sine, but if your running something real basic and not very sensitive it's prefect! I use it for cooling fans for various things.

Like I said and as you can see(blue wave on the oscilloscope) the final DC isn't a perfectly flat wave but it's real close for lights or fans or other non-sensitive gear. I wouldn't put a radio on this supply. But with parts or maybe if you have to go to Radio Shack it costs somewhere between free and 15 bucks.