Saturday, December 25, 2010

got a Blogger app for my Droid phone.

Just testing it. I started a build of a softrock rxtx ensemble. I'm excited to get it built. Hopefully I will be able to get it done.
Published with Blogger-droid v1.6.5

Tuesday, December 21, 2010

Eight Below

http://www.imdb.com/title/tt0397313/

Just watched this DVD last night with the wife. It's a very sad movie about some antarctic explorers who are force to leave their sled dogs behind when they evacuate to avoid some bad weather. I couldn't help but notice at one point in the movie, fairly early on, that they are talking on a radio that looks a lot like the FT-817.

Clip on Youtube Here is the specific spot of the movie with it. I can hope this link doesn't go down all I want but It'll probably disappear eventually, given the nature of it. If I find out it does, maybe I'll throw up a 30s excerpt, should be fine for fair-use clause. They have some pretty sweet, but old looking, base gear also.

Sad movie though, I don't think I'll watch it again.

Friday, December 3, 2010

Yeasu FTM-350R ramblings

http://www.universal-radio.com/catalog/fm_txvrs/3350.html
Just noticed this radio and wanted to make some comments. I actually found it by clicking an ad for associatedradio.com and then seeing the FTM-350AR had 220 capability. "Oh neat, 220!" I thought. Then I read that it was 1W. Well, okay it's a pretty feature packed radio, maybe there wasn't room for any bigger PA for 220.

I'm a little disappointed really. The 350R is a $500 radio, the AR is MSRP $780 with a ETA of 12/27/2010. At least they have a built-in APRS TNC (will it do regular packet or does anyone care at this point?) and a barometric pressure sensor. They are also bluetooth ready.

The bluetooth module to add support is $75
The "Internal GPS" unit is $75
If you opt for the "External GPS Antenna" unit instead, it's $70 but you have to buy a $60 cable and a $25 "External GPS adapter"

There's an oddball addon for it. I love oddball addons.
Yeasu FPR-1 Monitor Unit This is a pager sized device that works with the 350R, it can receive your 440band transmissions up to 1000' away. I might look for the manual online to try and get an explanation for this. $60

I'm still looking for one of these radios that can use a computer in the place of the remote faceplate. I've been considering attempting to do that with my Alinco DR600. If only I could find the weird 6-pin connectors they use. I may just figure out a cheap way of connecting to it without the connectors.

Saturday, October 23, 2010

Ham Radio Cellphone Network

I highly recommend this article to anyone, it really resonated with me. The article makes a good point that anyone can throw a wire into a tree and call CQ. But there was one key paragraph that sent my mind wondering. I quote:
Future developments in the non-amateur world of radio from that point included cellular technology and the transmission of higher speed data over the air. Commercial applications for broadcast radio and television have changed radically and now include the imposition of digital methods. Military applications for secure battlefield communication use satellite and terrestrial means like mesh networking for voice and data transmission. Our homes, restaurants and coffee shops are bathed in RF transmitted data that keep our mobile devices connected to the Internet.
 Sure, there's the High Speed MultiMedia HSMM experiments... although the working group for that has disappeared and the general attitude I see about it, over and over is that you can do more with Part15 than you can with the higher power afforded with part97. It's a shame really. I've also seen a couple rare web pages discussing experiments with DATV. Much to my surprise, the experimenters preferred DVB-S to ATSC.

I'm not saying that Ham Radio is completely irrelevant. There's a lot of focus on it's use in emergencies and getting ready to help out in a disaster. And that's great. We have digital modes that run with a soundcard interface on a computer and software defined radio. There is a fairly basic digital voice mode called D-star. That's the big developments lately. Other than that, operating is fairly much the same as it was 30 plus odd years ago.

Why not a Ham Radio Cellphone network? I did some searching and this is what I've come up with..
Okay, the article discusses the use of this stuff to "hack" people's cellphone connections and listen in to their traffic. It misses a point that is blindingly obvious to me.
  • European GSM cellphones have 900mhz as a band
  • American Ham operators have 900mhz as a band
  • Hardware exists to set up a homebrew cellphone base station
  • How cool would it be to set up a legal ham radio cellphone network!
KJ6GCG, Chris Paget, set up his system to demonstrate the vulnerabilities of the GSM system specifically by spoofing the network ID for an active carrier. It should be entirely possible to set up a "fake" carrier that will not interfere with any commercial one and run it on our 900mhz band. Possibly even restrict access to special SIM card programming that could be posted online for any Ham Radio Operator to access. GSM can be run without encryption entirely, it's another point that allowed Mr Paget to demonstrate the call recording. Running in this mode will avoid any trouble with the regulations on the merits of codes and cyphers. The 900mhz band in the phones should be completely unused in America, that option is there to remain compatible with European networks.

Imagine this: Your area sets up a Ham Cellphone node and various operators get a GSM quadband phone of their choice (probably needs to be unlocked). Now they can carry a form of communication around that allows them to contact other hams at any time. It will always work in an emergency. You could potentially allow for a "phone patch" operation. It would be beyond easy to put in an extension number to allow access to any attached repeaters, echolink, etc. Call ex# 270 to access the 147.270 repeater!

I wonder if the data connection works.. Hello hinternet! GSM-APRS? Text messaging? You could set up a truely cell based network with HSMM backhauls between each cell. Put the backhaul in the Ham allocation of 2.4ghz and have fun.

The OpenBTS project is what makes all of this possible. They use a software defined radio called the Universal Software Radio Project (USRP) along with their own Linux-based software to fully act as a Cellphone Base station. There is a blog written by the OpenBTS developers here.

Incidentally, The OpenBTS people have been running a small cellphone network at the Burning Man festival for the past 3 years or so. They get a special temporary license from the FCC and coordinate it with the phone company that covers (or doesn't, in this case) the area. The Wikipedia article references this but I can't find the blog posts that I remember where they talked in detail about it. This is the authorization for 2008 with temporary callsign WD9XKN.

Of course, after writing this whole thing I run across a Wikipedia page with GSM frequencies worldwide. Some of the allocations fall in the 900mhz band but it's not clear to me if there are any channels that fall completely into the 902-928mhz bandwidth that we are allotted. Can uplink and downlink frequencies be set to fall within the allotment? Will that actually work with any phones? I don't know.

Questions? Comments? Flames? Does anyone really read these things?

Thursday, October 7, 2010

There have been a couple of interesting developments recently that I'd like to highlight.


The first one, I'm most excited about it, is the announcement of the SDR-Cube Transceiver.
A Portable Software Defined Radio
Utilizing An Embedded DSP Engine
for Quadrature Sampling Transceivers
George Heron, N2APB   and   Juha Niinikoski, OH2NLT
Very Neat! This kit takes a SoftRock 6.3 SDR and provides a dsPIC with all the brains to do AM/SSB/CW. It's apparently built to be very easy to couple with a NUE-PSK modem for not only computer-less SDR but PSK operation too. The makers say it can work with other computer coupled I/Q SDR boards as well, so it should work with any other SoftRock. The case will come painted black and several kit options will be available. They are planning to be a source for the SoftRock 6.3 RXTX if you want to go with that option. Personally I'd rather use an Ensemble RXTX and have 3 bands.
I highly recommend anyone to check out the website here.

NUE-PSK modem. I kinda wish they had a keyboard built-in. It'd look a lot like an old Tandy Model 100 though. That wouldn't be a bad thing, I don't think.





Something similar is the Mobo 4.3 Project. I don't know a whole lot about this project so I'll let the page speak for itself:
An all singing and all dancing all band 5W HF Software Defined Transceiver based on the popular Softrock 6.3 RxTx kit.
The Motherboard, or Mobo v.4.3 is an addon board to plug onto the Softrock v6.3 RxTx, to transform it into an all band (160-10m) HF SDR transceiver electronically controlled via USB.  This project, which started in mid 2009  has now been through the initial development phase, the result being a nicely performing all band transceiver, with an exceptionally linear transmitter output.  Measured IMDR is of the order of 48dB at 1W PEP and a respectable 31dB at 5W.  

Sounds pretty neat but again, with this project you require a PC to run the radio. Now if we could combine these two projects somehow, that'd be really neat. One thing that really impresses me is the digital power/swr meter. It's the smaller board to the right in the above picture. If the mainboard detects a high swr, it can automatically reduce your power so you don't burn out the driver. How cool is that?




Finally, Wouxun has announced a new radio in their line-up. It is a dual-band mobile radio. Link to the image, the Ed that runs Wouxun.us has all the details. No pricing information on it yet.

  • Dual Receive (Truely, not dual-watch like the handhelds)
  • Crossband
  • Dual Frequency display
  • 50W
  • 999 channels
  • Remote head.. Mount radio somewhere else and just put the head on your dash. Looks like Mic plugs directly into the head also. Hope that's a standard feature and includes mounting gear.
Looks like there are going to be multiple versions like the handhelds. 218-260 is listed! So there's a possiblity there of 2m/222.. 136-174/218-260. There's also some weird stuff like the possibility of 2mhz-30mhz AM-only receive. Or 500-2000khz, Or 50-500khz all AM-only. I don't really see the point in it but there you go. Apparently FM broadcast is available too. So one option there gets you AM & FM radio. The 2-30mhz option is kinda pointless unless you want to listen to CB though!

Friday, September 17, 2010

Chumby Hacker Board






This is pretty neat. It's a Single Board Computer that is basically the guts of a small device called a Chumby. The hardware is all Open and it runs a custom distro of Linux. Specifications below.






  • Freescale iMX.233 processor running at 454 MHZ
  • 64 MB onboard RAM
  • Comes with 512MB uSD card with 100 MB Linux installation all ready to go
  • Dimensions are 3.9" (100mm) x 2.4" (60mm) x 0.75" (20mm)
  • 3.3V I/O pins can talk to most sensors, motor drivers, etc. No struggling with 1.8V levels.
  • Low power, fanless CPU draws only 200 mA at 5V
  • Built-in Lithium Ion/Polymer battery charger and 5V boost converter for portable projects
  • Three USB ports!
  • 1.9W mono speaker amplifier into 4ohm (0.1" JST onboard connector)
  • Microphone input (0.05" JST onboard connector)
  • LCD controller with 2mm output port
  • 3.5mm A/V output jack with stereo audio and NTSC/PAL composite video
  • Back of board has GPIO outputs on 0.1" header spacing, plug in an Arduino proto shield! Serial ports, ADC's, PWM, GPIO all running at 3.3v logic
  • Quadrature encoder connections onboard
  • 5-way joystick on-board
  • MMA7455 3-axis +-2G to +-8G accelerometer on-board
  • 3.3V TTL serial port for easy shell access
  • Full GCC toolchain is ready for you to download and get crackin'!
  • Schematics, Gerbers and original layout files are at the Wiki
All for only $89 at adafruit.

This could have quite a few uses for ham radio operators. Linux has integrated support for AX.25 Packet in the kernel. I've heard it's possible to set that up with a sound card interface. If someone made the software available this could end up being a very small Echolink or IRLP node. I wonder if the processor is fast enough to do simple software defined radio tasks? This could make for a tiny, full SDR with one of the softrocks or some other SDR kit. The CPU uses very little power.

My only disappointment is no onboard wifi. It's a small loss though. Not everyone would use it and it's easy enough to add a dongle on one of the usb ports.

Supposedly the board is only in beta right now so it's subject to revisions and has a limited production for now. I see a bright future for this thing.

Wednesday, August 4, 2010

Tuesday, August 3, 2010

Kenwood TR-9000 Problems

Frequency knob won't change? No transmit or receive? (RX/TX) PLL unlock?


I got this off of Ebay and it seemed to work fine for a little while and then it just died quietly. Everything appears to work but there's no receive (which was my first clue) and no transmit, that I can detect anyways. No transmit could be a problem with the PA but no receive, IMHO, seems to be more of a PLL issue. If so, then that should be my problem with transmit as well. Additionally, it seems pretty random but the main tuning knob will sometimes cease to do anything. I can change the display from the mic or by scanning it while this is going on but the rotary encoder acts like it's dead. I think this is related to my more major issue rather than being one on it's own.

I have this Service Bulletin from 1982 that I found here


I did perform the measurement with my oscilloscope and I think the radio needs the mod described. I'm not sure how to align the radio after I do it though. :/ It's been years since I took the electronics course so I'm not even sure I did the RMS measurements and calculations right.

Measurement at TP3 with .2v/div and .2uS/div. The bulletin above says the radio needs the mod if TP3 measures less than .5vRMS. I think this is right.

The alignment instructions state:
To align L6 & 7, first position the slugs flush with the tops of the coils, then alternately adjust those two coils for maximum output at the first peak into the coil ( fundamental frequency).  Then align L5 for maximum.
I'm fine up to the "flush with the tops of the coils" bit. LOL I'm not sure how I will continue beyond that.

I haven't attempted this mod yet, I want to get all my ducks in a row before I do it.
The offending circuit! X50-1620-11

Of course, there are quite a few electrolytics there, hopefully it's not a case of a leaky cap. I don't see anything out of the sorts there so far.

Edit: I'm not sure if this is the problem or not. I was measuring some voltages and there are several places where voltages don't match up to what the service manual says they should. The base of Q13 has 6.5v which is good but the collector should show 6.6v, I have only .7v there. :/

Friday, July 16, 2010

Android

It'd be pretty neat if some manufacturer made an HT with integrated Android touchscreen device. I could think of a number of neat things that could lead to, other than a pretty interface. A handheld, self-contained APRS device for starters. A packet softmodem could be implemented and then it'd just take linking that to an APRS program. It's not required but if wifi and/or bluetooth was implemented then this could even gateway packets to the Internet when you have access to an AP or a bluetooth tether to a phone. With those, you could have access to Echolink and even do a short term Echolink node if necessary. You could have a fairly long term voice recording and playback mode. If source is available for radio control module then it would be easy to add an ID timer or CW ID. SDR would be a natural fit and could even make the component count lower. A Dstar hand held would be interesting with this sort of integration as well. D-rats could run right on the radio. Also DPRS.

  • Packet
  • APRS
  • Wifi and/or Bluetooth?
  • igateway
  • Echolink
  • Extensible interface/functions
  • Voice recorder
  • CW ID
  • SDR?
  • D-star?
    • D-rats
    • DPRS
    • ???
Never going to happen, but that's something that'd be very interesting.
I imagine that a simple 2 meter HT with an android device glued on to it with no special features beyond a control program and audio I/O would be $800 or something ridiculous like that with how low the demand would be. (Even among licensees)

Maybe on one of those multiple thousand dollar HF radios. They can say "Look we glued a $100 android device on the front (cost us $50 in parts), give us another $500 please!"

Tuesday, July 13, 2010

no money, no problems?

This hobby can really suck when you're unemployed and have no money for radios, other equipment, accessories. I've let so many opportunities fly by me because I don't have the wherewithal to take advantage of them. I'll probably forget by the time I do also.

Unrelated whining aside. My wife has given me a good idea to try to attract more blood to the hobby by trying to start a club at the local high school. I think this is a great idea and maybe something clubs should start looking into for their area. Of course, chances are it'd bomb out completely.

I've begun trying to convince a friend of mine to get licensed. Actually a little bit more likely cajole. I remember a story from my old study material, "Now You're Talking!".. About a whole family who was licensed including their 5 year old. Surely if a 5 year old can do it, so can he! Also, the tests are easier than I remember.

Tuesday, May 18, 2010

IC-9100

This is a new, very expensive, HF/VHF/SHF tranceiver that Icom is advertising and potentially going to release later this year. It can do HF+6m, 2m, 70cm and 23cm with an optional module. Additionally it will have a module for D-star that will allow you to do D-star on 10m,6m,2m,70cm and 23cm.

Wait, is D-star even allowed on 10m? The brochures say it's possible to use the DV mode on 28mhz but I was under the impression that the maximum bit speed you could run on 10m was 1200baud. D-star runs at 4800baud. The transceiver has not made it's way through the FCC according to unversal-radio. I wonder if anythings going to come of that.

More information:
http://www.ab4oj.com/icom/ic9100/IC-9100_prerelease.pdf
http://www.ab4oj.com/icom/ic9100/ic9100pre.pdf

Rich man's hobby

Repost from KE9V's blog:
A quick review of some of the equipment that debuted, was announced, or made an appearance at Hamvention this year:
  • Icom IC-9100 when it becomes available the rumored price is $4000. This is yet another in a platinum-plated Icom line that includes the IC-7600 ($4000), IC-7700 ($7000), and the IC-7800 ($13,000).
  • The Yaesu FT-DX5000 in several flavors that retail from $5000 to $6000.
  • Kenwood’s TS-590S at $1800 retail (available in October) is said to replace the TS-570S. This seems like a fairly reasonable price but don’t lose sight of the fact that the 570S that it is replacing last sold for $989 before it was discontinued.

 I agree with every aspect of this. I also like the challenge near the end of his post where he challenges people to tally up the cost of equipment in their shack and compare/contrast it with how much they spent on their wife's wedding ring. I guess these are the prices that the market will bear.. but will the hobby?

Go Check it out.

Monday, May 17, 2010

Alinco Radios

I know Alinco isn't as popular as some other equipment makers but they do have a couple of interesting new radios out. One that I saw and played with a bit at the Hamvention is the DJ-G7:

I think this is something really neat because it not only does 2m and 70cm but also 23cm, or 1.2ghz. You don't really see a whole lot of equipment that does 1.2 so I thought that was really cool. It does 2m/70cm at up to 5w and 1.2 at up to 1w. Additionally, it's true dual receive and it has a wideband receiver that goes from 530khz to 1.3ghz, minus analog cellular. (824-849.995,869-895.995 blocked) I thought I read at the show that it was all-mode receive, but I can't see that on their website now. It is just showing AM/FM/WFM.

Go check it out.



Additionally, and I was tuned in to this by someone on the softrock40 mailing list, Alinco has brought out a DJ-X11 communication receiver. It looks a LOT like the DJ-G7 actually. If I had one of each in a drawer, I might accidentally leave the house with a scanner instead of my HT!

This covers from 50khz(!) to 1.3ghz, all-mode. AM/FM/WFM/SSB/CW. It is dual receive but it appears that the sub-band only covers 118-171 and 336-470. AM/NFM, blegh. I shouldn't complain, dual-receive at all in a communication receiver is pretty rare anyways. This radio makes up for it by having a really cool feature. It has IQ and 10.7mhz IF output. With the IQ output, you can plug directly into a soundcard and use it directly as a SDR (Software Defined Radio) Very cool! I'm not familar with what the IF output could be used for but it's nice to have anyways. Again, this is something very rare for this sort of thing. It also has a frequency counter and "Flash tune" feature to tune into nearby radio signals. You can get a cable to control all functions from a computer. Very nice indeed.

Go check it out.

Sunday, May 16, 2010

Paging all Hams

http://oh2lak.blogspot.com/2010/04/200-w-paging-transmitter-usability.html

This is cool. It's a homebrew paging network running on Ham radio frequencies. I believe they have this set up to send DX clusters. That's okay I guess but there's all sort of uses this could be used for. Weather alerts, Skywarn, club reminders, emergency contact, or even getting the attention of someone away from their radio.



I'm not sure if it's related to the above project, but here's one using a modified commercial radio to send the pages: http://oh7lzb.blogspot.com/2010/03/project-pocsag-paging-network.html



Apparently some pagers can be reconfigured to work in the 2m band. The pocsag "modem" can be implemented on an Arduino which is a cheap multiprocessor development board.

I saw some pagers in the flea market at the Hamvention this weekend so the used hardware is definitely available. I don't know what kind of prices they were being sold at. I saw plenty of commercial VHF, UHF and 800mhz radios there also.

More Information:
http://www.qsl.net/kb9mwr/projects/pager/plan.html
http://www.scribd.com/doc/16190767/ham-radio-pagingputting-pocsag-on-packet

Wednesday, May 5, 2010

ROS new Digital Mode


Video from Youtube of the ROS digital mode that's caused a bit of a raucous. More info here. I'm going to stay out of the discussion.. I have no way to use it, yet. I am humored by the sound of it. It kinda sounds like an old, run down, out of tune music box. I'm half surprised that the FCC's disagreement with it is about a spread-spectrum quality rather than a musical one! LOL :)

Tuesday, May 4, 2010

Weird kit from Kenwood...

Kenwood had some neat kit that they were experimenting with in the past. There's this thing:

The Kenwood VC-H1


Kinda looks like one of those portable TVs doesn't it? It was for portable SSTV.  The camera on top was a 270k CCD that could be turned 360 degrees and detaches for connection of an external video source. The LCD screen was 1.8". This unit was capable of storing up to 10 pictures in its memory and it was compatible with 8 different SSTV modes. Even though the manual says that, it can only send in two modes; Robot 36 or "Fast FM". The latter requires a 9600 baud connection with your transceiver. The manual lists 5 Kenwood transceivers that it works with in Fast FM mode, I suspect it would work with anything that can do 9600 baud though. It is capable of subtitling your pictures with your callsign. It can also automatically transmit every 3 minutes.

Pretty neat little device for someone who wanted to do portable SSTV. Put some AA's in, plug an interface cable into your HT, and go.



Then there's the Kenwood IP-100 "Illustphone"


If you do a Google search for this you'll end up with a bunch of pages talking about an ipod interface for your car or something. Rigpix claims it "allows transmission of alphabets, number symbols and pictures which are drawn on the pressure sensitive tablet." But there's nothing about transmission mode. Does this work in SSTV or some sort of FAX mode? Is that a thermal printer of some sort on the back of it? When were they sold and does anyone still use it? I may never know.









Kenwood also made the CD-10 Call sign Display.

I talked about that in an earlier post though. I'm kinda sad this didn't catch on. Just because it's neat and it was 20-30 years ago that we had the capability to have a callsign automatically transmitted. This is the sort of thing that D-star is only now making possible again. R & L actually has one of these for sale.




All pictures courtesy of RigPix.com
Used without express permission, I'll take them down if there's an issue though.
Oops, I was unintentionally linking directly to the pictures on their website, I thought I was hosting them on here when I pasted them in. Fixed that now. 

Monday, May 3, 2010

D-Star

The wikipedia page for D-star is pretty interesting: http://en.wikipedia.org/wiki/D-STAR

I don't think I was aware that it was created as long ago as it was. It started as a research project by the Japan Amateur Radio League in 2001. Also, apparently it's been used for at least one satellite QSO in 2007. I don't know how popular that is compared to analog modes but that's pretty neat. There's a D-star capable microsatellite that is suppose to launch this October, 2010.

I'm impressed in how low the data speed really is, and yet they manage to get decent audio through it. I guess the data stream runs at 4800bit/s. 3600bit/s is voice audio (with 1200bit/s forward error correction, so only 2400bit/s for the audio) and a spare 1200bit/s for other data. A different modulation technique can transfer 128k but only on 1.2ghz.

Pretty much the entire standard can be implemented except for the chip that encodes the audio to a data stream. This is a proprietary chip, only available in hardware form, and noone's allowed to make an open source implementation of it. There is an effort to make an open source audio codec but this will create digital radios that can't talk to each other. With such a codec you'll have a dstar radio that can't talk to icom based dstar radios, although you'll be able to transfer regular data just fine. http://codec2.org/

GB7MH has been able to use this to make a d-star repeater without requiring the audio chip. Decoding the audio isn't necessary for the repeater functions. It's still possible to fully handle the rest of the D-star features.

Some people have been able to build homebrew radios using the UT-118 DV adapter that was originally intended on being installed in Icom radios.

Honestly, all this technology makes me very excited. I refuse to buy into it with a proprietary licensed codec however. Ham radio these days is way too much a commercial, consumer electronics field. The usage of a proprietary codec really flies in the face of the hobby and I refuse to support it. Godspeed to Bruce Perens and David Rowe. Hopefully sometime in the near future an open source codec will exist. I wouldn't scoff at an Icom radio, or any other, with an open source digital voice adapter in the place of the UT-118 one.

James Hall

Link dump

Blog by pictures...... go!

http://www.zerobeat.net/g3ycc/ledswr.htm
http://www.qsl.net/va3rr/sw30/30metres.htm


http://www.qsl.net/wb1gfh/antenna.html aka "THE $4 SPECIAL"



http://www.w1mv.org/ladder.htm "The Lure of the Ladder Line"

I'd like to find a good schematic and detailed, easy to understand, guide to building an antenna tuner/transmatch.

...To Be Continued


Wednesday, April 21, 2010

DCS Callsign, MDC in the 80s

Wow, You learn something every day. Apparently at one time DCS would let you transmit an ASCII ID too. Kenwood made a box called CD-10 that would plug into a regular radio to display callsigns received in this way. CD-10 Manual

Looking around I see reference to an HT made in the mid-80s that transmits the IDs. Kenwood TR2600A Very neat stuff. Apparently it sounds like MDC which is a system that is or was used in commercial radios used in police cars to transmit a station ID at the beginning of every transmission.

This is the kind of stuff that is only just recently available again and even then only if you use Dstar. It'd be pretty awesome if the DCS ID thing came back on the analog side I think.

Edit: Kenwood's TM211 had support for transmitting the IDs. Via the TM211 manual (Section 5) I see that it assigned letters and numbers to various DCS numbers.

Wednesday, April 7, 2010

My pixie II kit I built the other day. It's not "Done", I have some work to do on it. I really need a small bit of coax to connect to the antenna jack, which is a RCA jack on this. Frequency is a little off of 7.040. I haven't had a chance to check where it is exactly.

I haven't figured out how to measure it with my oscilloscope I bought a couple months ago. It's an old 60mhz analog scope that I think was formerly used at NASA at one point (Whoa!)

Waveform on receive, measured at antenna. The oscillator in this is always running so there's no chirp when it is keyed up. Measured at .1v/div.


Waveform on transmit, again measured at antenna. 2v/div. Nice clean sinewave. Picture is dark because I set my camera to 1/125s so not much light was collected. More than enough for a nice sharp image of the trace even though I'm holding the camera. :)

Blogger is giving me really annoying problems trying to format this with the pictures in the compose view. >:(

Monday, April 5, 2010

Programmer scanners

You know, I always wonder why noone has brought out programmable scanners. Yes I know there are scanners that are called programmable scanners. Really old scanners used crystals and you had to have one for each frequency you wanted to monitor. Then someone built scanners that had PLLs and digital readouts and direct entry of frequencies and called those programmable scanners.

I want programmable scanners more like my graphing calculator. Is that too much to ask? Give me a nice sized screen, at least a basic interpreter and a computer interface by default. Even if the programs couldn't be built interactively on the radio itself, I could live with that I guess. Even something fairly low power like a z80 level of performance would be better than the fixed, closed systems we have now. Higher power options would add even more uses, albeit possibly at the cost of some battery life. Imagine one with a Cortex A8 ARM processor running Android or Linux doing software decoding of digital communications right on the scanner itself. Add a GPS module and you could have a portable APRS receiver that can show your location compared to others. (I'll admit this idea is nicer if someone would add it to a transceiver instead)

A computer serial interface is just something that every scanner should have by now whether most of its intended audience would use it or not. I'm rather certain all units have some sort of microprocessor built in that could at the very least give serial control and read out with a little programming and probably less than 50 cents worth of parts.

My Icom R3, which is one of the more advanced scanners I've ever owned, doesn't even have computer control. I can read frequencies out of it and write new ones in but I can't control it and even if I could, the interface is the speaker out.

Bluetooth would be nice too. I've seen that the VX8R has an optional addin for bluetooth but it's MSRP is $99. I wonder how much of that is justified or if it's mostly price gouging since pretty much noone else is offering it. From what I've read the bluetooth is exclusively for hands-free operation. Not a bad thing I agree but would it kill them to add some serial protocols to it so that you can pair it with a computer and control the radio and/or use the packet without additional cables? Probably.

Sunday, April 4, 2010

Pixie 2 QRP rig

Recently acquired two of these boards with all components for building the Pixie. I got crystals for 7.040 with them. The documentation says they can work from 10m-160m depending on one inductor and the crystal. From what I've read you really need to make more modifications than that to put on higher up than 40m. I got the kits from HSC electronic supply. The kits include inductors for 40m or 80m but crystals are separate. I built one kit and a friend of mine built the other one. Now all I need to do is learn morse code again! I haven't touched it in 10 years or more and I just barely knew it back in the day.

It was, nonetheless, very satisfying to build the circuit. I also had fun diagnosing and fixing the problems with the other circuit. I put mine in an "astonish-mint" tin (altoids clone from Meijer) and my friend put his in a neat little wooden box that had some drill bits or some such in it at one time. 

Sunday, March 28, 2010

Ham Wars IV: A New Blog

First post on a new blog for ham radio related stuff. Let's see if I actually use this one.