Iris Transmitter V1.1

Posted on 2012-12-17 by Nigel VH

So, as you know from previous posts, I’ve been working on a new custom transmitter module. After the first revision, I found a few things that I’d like to fix, and a few things I’d like to add. I ended up fixing the fixes and adding the additions, making the board a little smaller, and came up with Version 1.1. Guess what?! The boards just came in!

Revision 1.1 includes a boost regulator to generate the 5V needed for many aspects of the board, operating from 2 AA batteries, RF output filtering was improved, and total board size was reduced.

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Iris Transmitter – APRS

Posted on 2012-11-05 by Nigel VH

I got APRS working in a state I’m pretty happy with on my transmitter board. Granted, it’s a fairly low power transmitter, so it can sometimes have a hard time being heard, but it got a few good points through on a drive I took this last weekend.

For reference, I had it connected to a 5/8ths wave mag-mount on my car for the drive.

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Spot The 2012

Posted on 2012-10-17 by Nigel VH

So, I had my car in for service the other day, and they gave me a loaner. Turns out it was a 2012 Forester. Granted I don’t know what the trim level was, but I have to say the Forester was disappointing in terms of the interior.

Here’s a photo of the Forester.

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And here’s my Outback…

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Iris Transmitter Part 2

Posted on 2012-10-17 by Nigel VH

So, for a bit of an update on my transmitter project. I’ve made a few minor wire fixes to the board. Mostly just adjusting what outputs on the ATmega are connected to what.

Most of the work involved has been software. I’ve got a ham friend working with the same PLL chip, and I’ve used his code as an excellent reference on interfacing with the PLL.

I’ve also got an existing APRS implementation, however it was blocking code, so I’ve been spending a lot of time rewriting my APRS implementation to be interrupt driven. Hopefully I’ll end up with a lot cleaner APRS generation.

I’ve also redone the filters. The original filters I had designed had been, to put it lightly, awful. They were mostly an RF absorber. After replacing the filters with something reasonable, I’m measuring about a 1/4W CW output. Maybe just a little higher.

The processor is an ATmega328P, which talks to a ADF7012 PLL synthesizer to generate the 144.39MHz signal. The signal is modulated by means of a VCXO acting as the reference for the PLL. Total output power was brought up by means of an RF FET amplifier stage, to a level of approximately 250-300mW. The board required a power supply of a regulated 5V input, and included a linear regulator onboard to supply 3.3V to the ADF7012.

Overall, so far I’m impressed with the results. Hopefully soon i’ll have APRS working totally, and I can start transmitting. Who knows, maybe I’ll show up on the map in your neighborhood.

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Legalese Part 5

Posted on 2012-09-11 by Nigel VH

Last time on Legalese… *cutscene* bad shit happens *intense music* other crap happens *cliffhanger*! … and now the conclusion.

Yep, that’s right, FINALLY the conclusion.

The investigator from the DOL emailed me yesterday to let me know that the towing company has now decided to not pursue the lien against me. (After I told them a number of times on the phone, sent them a certified mail letter including copies of the documents saying I’m not responsible, a DOL investigator telling them that my report of sale is valid and giving them 10 days to respond before further action is taken by the DOL.)

I’m extremely glad to have this whole deal over. However, I’m certainly going to be requesting copies of the reports the investigator has, for future reference in case this becomes an issue in the future.

It also is clear to me that the towing company was attempting to extract money from me because it would be easier than doing their job properly, and because they can claim what they like. It’s unfortunate, but they have the power in this situation. All they have to do is claim I owe them some money, and it’s my job to prove that I don’t, meanwhile they’re attempting to rack up fees against me because I didn’t pay them off the bat, and if I were to just ignore them, then they’ll go to collections and fuck my credit. I have been essentially at their beck and call, for no reason other than some other guy not being a responsible citizen. It’s an immensely frustrating situation.

I’ll also admit that for about the first week of this situation, while I was insisting to the towing company it’s not my deal, and not being able to find anyone with official capacity to tell them to knock it off, that it messed with my head. I was not a fun person to be around (my fiance can testify). That first weekend, I managed to get a little introspection time in and chose to let it go. I still need to fight it, I’m still not going to pay them, but I’m not going to let them make me into an angry person. Since then I’ve been doing a lot better, and am now quite happy to have the whole thing done with.

In any case, if you end up in a situation like this, if the tow company won’t back off, call the DOL right away and file a complaint. I waited a while and it just protracted the whole thing.

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