I'm setting up an HF rig at home.  I'm about 15ft from a cold water pipe.  The HF rig is currently powered by wall current, but by Field Day it will be powered by batteries which will be constantly charged by a power supply.  The batteries will be connected to a Radio Shack power bus, which would then connect to all my 12V equipment including my HF rig.  There is also an antenna tuner in place.

Where should the ground go?  I'm torn between connecting it to the tranceiver directly and connecting it to the black terminal of the array of batteries.  Should the batteries be grounded or not?

It's too late for this year, so I'm trying to design an auxiliary power supply for next year.

The equipment I want to run is limited -- a 5W HT in a base station charger, an AEA PK-232 TNC, and an old laptop.  Unfortunately, the only way I can power the laptop is through an inverter so that alone is 75W of power.  The other equipment comes up to 65W for a total of 140W, or 10A at 13.8VDC.

I found a nice (but expensive!) DC-to-DC converter which produces a regulated output of 13.8VDC at 80% efficiency from 20-28VDC.  Here's where I'm confused, though.  Do I need 600Ah of capacity (10A*48h*1.25) in order to run this thing for 48h straight?  If so, is that at 12V or 24V?  Since I'm supplying roughly twice the output voltage, wouldn't I need roughly half the capacity?  Either way, that's an *expensive* amount of batteries.  The largest battery I found in a quick web search costs over $150 and... well, I'd need a few of them.

Am I doing something wrong, or is it really this expensive?

The wall charger doesn't work -- I had a similar experience.

However, the drop-in charger rocks.  You can use it to use the radio as a packet station, and you can also use it to charge batteries while you're walking around with your HT.  I have two Kenwood drop-in chargers for two different models, and I'm very pleased with both.

If you run Unix at home, you can still do all that wonderful APRS stuff.

Linux has great support for soundcard modems, and FreeBSD can be made to work as well.  There is an APRS application for Unix that is head-and-shoulders above the WinAPRS and MacAPRS packages I've used, and that's Xastir.  No hassles about shareware stuff -- it's free as in beer and free as in speech.  You can save your preferences the first time you use it, unlike those other programs.  Also, it downloads maps from Tiger and Terraserver for your specific location.  It has great support for Internet APRS -- everything from RF->IP to IP->RF to just spectating via the Internet is supported.  It's wonderful stuff.

If you're asking about the best place on the Internet for information on packet radio, I'd say

http://www.tapr.org/

Googling for "packet radio" can also be helpful.

What exactly about packet radio would you want to look into?  Maybe asking in the Digital forum would be more appropriate.

Just a thought, but have you considered using the Internet or the telephone for your "last mile"?

There are quite a few radios that have computer programs allowing you to control the entire radio.

Stick a computer at your cousin's and connect to it over the internet via VNC (Virtual Network Computing -- use google.com to find it) or PCAnywhere or whatever you like.  That combined with something that translates the audio output of the station to something on 2M and you might be in business.

The backyard I have to work with is 25 feet by 9.5 feet, and I've decided to string up a dipole on the clothesline.  

It's the right length to fit, but it'll be maybe six feet off the ground and six feet from the house.  

How badly will the ground and building affect the antenna's performance?  

I won't even ask about what'll happen when the YL throws the laundry over the antenna. :-)

17m is what I was hoping, because I can mount a dipole on the clothesline poles -- they're 25ft apart, and the dipole's 23ft.  Now to shop rigs. :-)

Thanks for the suggestions!

I moved from a fourth-floor apartment with a balcony and very nice GPS and 2M reception to a basement room with zero GPS and very little 2M reception.  However, I do have easy access to a tiny backyard (25ft x 9.5ft) and permission to place an antenna or two providing the neighbors can't see it and it doesn't interfere with the clothesline.

I was pondering a mobile antenna with a tripod or a folded dipole when I came across the Isotron advertisement in the latest AES catalog.  The Isotron antennas have gotten good reviews on the net (especially here at eHam) so I'm willing to try one -- which means I have my choice of bands from 80m to 6m, and that brings us to the subject of this topic.

I live in Martinez, CA, (grid square CM88wa) and I'm primarily interested in reaching folks on the US East Coast.  I'm not passionately excited about DX but I haven't had any experience with it, either, so there's no reason to stop there.  Unfortunately, I have a rather sizable hill directly (200m) to the west and there's a decently-sized hill a bit (1000m) to the east which is a bit of a minus, I suspect.

What bands are easiest for me to work consistently and make interesting contacts, given my physical restrictions and my preferences?  I'd like to work CW, SSB, and perhaps packet or FAX if that's reasonable to try as a beginner.

Any help you guys can give would be greatly appreciated.  This site is the best when it comes to finding out answers to interesting questions.

I've compared the TR-2600A with PK-232 to the TH-D7(G) and found the former to be a bit easier to tweak for added sensitivity.  If I can score that cradle, I suspect this packet station setup will work for me for quite some time.

Thanks for your input.  Your comment inspired me to look for the base station, and that's going to make all the difference.

Ah hah.

Further on in the manual, under "Optional Accessories", I found this:

"1.  ST-2 Base Stand
  * Built-in quick charger about 1.5 hours with full
    charge indicator.
  * Full operation while charging.
          Separate Battery Trickle charge and power feed
          for extended base operation.
  * Drop-in connections.

 2.  MS-1 Mobile Stand
  * Cigar Plug for instant connection.
  * Full operation while charging (trickle charge only)
          Separate power feed for extended operation.
          Built-in illumination for keyboard.
  * Drop-in connections."

Either of those plus the VB-2530 25 W RF Power Amplifier and the TU-35B Repeater tone unit would make this thing far more useful.

If you still have accessories or know someone who does and woh is willing to sel them, please let me know!

A quote from the manual:

"During charge with the supplied charger, DC power to the TR-2600A is automatically OFF, so the TR-2600A can not be operated."

This matches my experience with the unit.  Do you remember how you made yours work?  Were you perhaps using another charger?

Thanks!

I have two Kenwood HT's -- a newer TH-D7 and an older TR-2600A.

The TH-D7 can run on wall power continuously.  A wall wart to 13.6VDC to a PG-3J to the unit and it's all good.

I don't know about the TR-2600A.  I bought it secondhand and the charger
connects to the battery, not to the HT itself.  Does anyone here know how
to connect this to wall power so it can run continously?  It's going to be attached to a TNC for APRS and other packet stuff until I can afford a 'real' radio for home.

Thanks!

I don't know much about Ohio and email, but I have been spending some time learning more about APRS.

If anyone here has considered trying to build an implementation of the APRS protocol as based on the specification, I'd love to hear about your experiences.  So far I've felt let-down -- I expected the kind of specification that I'd been spoiled with in the Internet world, but this one seems chock full of errors, inconsistencies, and contradictions.  Once I'm done building my implementation, testing it against the packets in the real world, and noting the differences, I look forward to contacting the APRS Working Group folks and comparing notes.

Anyone else?

While there's tons of stuff out there for Linux and Windows, I can't seem to find much software available for FreeBSD users.  Linux has the AX.25 hack that makes things kindasorta work, but there's nothing like that currently available for FreeBSD.  Some web searching turns up some old emails where people discussed adding AX.25 support to FreeBSD, but nobody actually got around to "doing it right" and adding it to the kernel.  I'd love to get hold of some user-mode and kernel-mode software to mess with packet radio and FreeBSD.  If anyone has any suggestions, please, let me know.  While I know it is possible to do Linux emulation, I'm really hoping to do this natively if at all possible.  Also, since my firewall will be running OpenBSD, I'd like to stick my TNC right on the firewall as yet another interface.  If anyone's thought about _that_, please feel free to share.