JacobsTribe

I’m terrible about actually updating this thing with any kind of frequency.. Well, I migrated the webserver, it was a Sun Ultra2 running Ubuntu 6.06, which very recently went out of support. Software upgrade was a no-go, so the migrate to modern ubuntu LTS and a dual P3-600 was necessitated. It has taken a couple months from first migrate until I bothered with migrating this weblog, so you can see where my priorities on this thing are (if they weren’t clear already from the frequency of my posts..) Due to personal issues that have been tying up a lot of my time, I haven’t had much time to occupy myself with the hobbies that I used to enjoy. However: I’m still enjoying amateur radio, currently studying for my extra test. Amateur radio details can always be found at QRZ under my callsign. I’m still enjoying film photography and my makeshift darkroom. I plan to write a mini-howto on darkroom photography for beginners on one of the new “pages” at the top of the screen. There are a lot of things that I wish I had known going into that hobby that I do know now. I also plan to move all of the schematics and project details out into pages as well. I’ve been lax on my nixie & VFD clock hobby lately, I just got bored with it. Lately I’ve been picking up the soldering iron for amateur radio stuff, but I have quite a few people asking for nixie clocks and will probably get back into that before too long. The next two nixie clock projects on the agenda are: A “feature-less” clock” which I can send to a remote location pre-set and will never need to be re-set (using simple batteries, RTC & TCXO).. The 2nd revision of this will re-set itself periodically via WWVB. My juggling hobby has gotten the short-end of the stick this summer due to the above-mentioned personal issues, I’m usually a fair-weather juggler anyways.. but maybe I’ll catch up on my juggling this winter instead, who knows. I’ve also picked up an interest in 3D. I’ve been playing with 3D photography for a number of years, via homemade contraptions as well as commercial cameras. I view the resulting images either via shutter-glasses on a CRT or via sending to snap3d to be printed onto a lenticular print. Just recently I discovered that I can display the consumer 3D movies (Avatar et al) on my PC-based 3D shutter glasses setup. This is pretty darn neat. Anyways, hope to take the time to make some format changes to this site pretty soon to make it more useful.

It’s been awhile again, I just wanted to log in quickly and upload the final schematics for the soundcard interfaces for both the HTX-202/HTX-404 and the Swan 500c. Both radios presented unique challenges, and I didn’t see anything like a usable schematic for either of these radios posted elsewhere, so here they are. For interest, the HTX-202/HTX-404 radios use a powered condenser mic instead of a dynamic mic, thus the reason for the NPN transistor driver. It’s worth pointing out that the input of the transistor is only going to see the positive side of the audio AC waveform, so we are losing half of the waveform. APRS/Packet radio doesn’t seem to care (I assume that the waveform is symmetrical?) I haven’t tried it yet with any other modes. Like other HT’s, the mic-in is shorted to radio ground via a resistor to provide PTT. Additionally, there is an issue with driving a high-impedance load on the speaker output of the HTX-202/HTX-404 for any length of time, where the speaker power amp will fail. I have resolved this issue by updating the HTX-202/HTX-404 schematic with an impedance matching transformer.

On the Swan 500c, the primary challenge is to do with the PTT relay itself. I was unable to get the PTT relay to actuate through a diode at all, so that ruled out high-voltage transistors and meant that only a relay would do. I really wanted to avoid a powersupply on my interface board as well, so that pretty much limited the available component for PTT on the interface board to low-power reed relays. I found that by installing a 1N400X to protect my relay from the heavy-duty Swan relay, and additionally current limiting with a resistor, I am able to actuate the PTT without burning out the reed relay.

I completed my homemade T-network antenna tuner, I’m able to get on 20m & 40m with my Swan 500cx now with it. I think I’ll need to install a separate smaller coil if I’m going to get on 10m.

After spending a great deal of time studying the Swan Compendium, I’ve got my 500cx outputting 100w CW on 20m. This qualifies as “about halfway works.” It’s a good start, though.

I recently got the idea to try hooking up my 2m rig, an HTX-202 to my PC for APRS. I’m thinking this will be a good stepping stone to setting up for PSK-31 on the Swan on 20m. Building the adapter to the HTX-202 turned out to be quite a bit more complex than I initially thought it would be. Here is the final schematic for the HTX-202 <-> soundcard adapter, based off of KD5ZUG’s adapter but with some necessary changes based on the unique challenges that the HTX-202 offers. My HTX-202 is now happily packeting away on 144.390!

I’ve been away from Nixie clocking for a while, I guess my mind has moved along to other things. There are still some half-finished interesting nixie clock projects on the shelf, when I get a chance to finish them up and draw their schematics (and clean the code up some) I’ll be sure to post them here. A few months ago, I got my general class ham radio ticket (W7ATJ) and that has been eating up some of my time. I’ve been operating on 2m & 440, with some serious attempts at AO-51.. Scavenging up a shoestring budget ham radio setup. I’m currently running an HTX-202, an HTX-404 (which I had to repair… service manuals are really awesome), and a chinese plastic wonder PX-2r. I found a dual-band j-pole on ebay for $10 and a 35w class C 2m amp for $3. There are some real bargains in ham radio if you keep looking. Anyways, my dad (WV7F) recently finished fixing up a Swan500 for me, so I should be operating on 20m before too long. Also, I started getting into developing & printing b&w film at home in my XYL’s laundry room (She’s a saint).. What a learning curve that has been! But I’m finally starting to get some really great results.

Here’s an ATMega88 based VFD clock that I just completed. This is mostly based on the old ATTiny2313 nixie clock code, and the schematic is actually simpler. Credit goes to Stanislav Pechal, Cestmir Hybl & Limor Fried, all of whose code found their way into this clock. I used readily available IV-11 & IV-6 tubes in this project, the project files can be found here:

http://www.jacobstribe.org/files/6-digit-VFD.zip

I thought that I would finally add some content to this blog, so here are two ATTINY2313 based multiplexing Nixie clock designs. Source code, compiled hexfiles, and schematics are included in the zip (along with readme).

Brief summary: Mike Moorrees’ MC34063 MK1.5 high-voltage supply is used to drive the nixies. The nixies are multiplexed via MPSA42 & MPSA92 high-voltage transistors. The ATTINY2313 drives a single 74141 nixie driver IC, which is bussed to the entire array of nixie tubes. Additionally, a piezo alarm is added, as well as an AM/PM indicator, and an Alarm ON/OFF indicator (for the 4-digit version). This code is pretty tight. I think that to add more functionality (such as leading digit blanking, or optional 24hour clock mode) would really require a larger microcontroller at this point. Credit goes to Stanislav Pechal & Cestmir Hybl, whose software was used as a starting point in this project. You can find these at:

http://www.jacobstribe.org/files/4-digit-12hr.zip

http://www.jacobstribe.org/files/6-digit-12hr.zip

Last night, I discovered that my Verizon FIOS connection doesn’t require its special router. I’m not sure why I assumed that it did, aside from the fact that disconnecting the Verizon router and attaching anything else seemed to yield absolutely no connection. It turns out, however, that if you release the DHCP lease before disconnecting the old router, then you can obtain a new lease just fine.

Take a moment to check out my Nixie clocks over at http://www.jacobs.us

Big News: I decided to put the wordpress weblog back on jacobstribe.org – I was getting a lot of emails from people who thought I wasn’t using the domain.. So, I thought I’d put something visible to cut down on the number of emails.

This webserver is a Sun Ultra 2 with dual UltraSparc Ii-300′s and 1.5gb of ram, running Ubuntu Linux.

This last weekend, I discovered that UHF Analog broadcast is still continuing without interruption in Wenatchee, WA. Apparently the digital switchover didn’t apply to UHF? If anyone knows anything about this, I’m very curious.