Thanks for the ideas!

Its a good idea to ask others living in the area if they experience any interference.  I know from reading plenty of postings on sites like eHam that some lines are kept in good condition and some are very RF noisy.

I have read some research about the EM fields around those lines, and actually I've played around a bit with a milliGauss meter.  If I knew the current carried by those lines I could estimate the field strength 1/2 mi away and see how that compared to some of the "suggested safe" levels people have proposed.

This will be my first house, and already I can see how it can be difficult to find quality housing that still allows antenna installations  It strengthen's my position towards always buying older houses:  1) older houses are found in older, settled subdivisions that most likely were established before CCR's became "fashionable"  2) older houses have alot of the kinks worked out, most any major construction screwup is revealed within 5yrs.

Anyway, thanks again for your advice

Mark
KC0HBM/4

I (like many of you were once) find myself as a new college graduate and newbie engineer looking to buy a house before I get married in a few months.  Of course, I cannot afford my own 100 acre lot with half-million dollar dream house, so I am actively looking on the used market.

One of the big criteria in a home is the ability to put up antennas as I see fit (no CCR's).  Luckily, I have found many nice homes that are in older neighborhoods that don't carry such restrictions.  I recently came across a nice 1800 sq ft home on about an acre lot.  It is in a group of homes just outside of town, and each home is surrounded by trees so you have some privacy.  The problem: there are a set of high-tension power lines about 1/2 mile away.  Is the proxemity of these lines going to pretty much rule out my ham activities?  How can I tell exactly how much noise is out there?  

I would really appreciate it if anyone can share some insight on this dilemma.  While I'm only active on VHF/UHF now, I want to keep my options open for HF in the future.

Thanks in advance,

Mark
KC0HBM

Unfortunetly I can't remember the individual's name, but I have seen an HF antenna install that mounted to the body of a 98-99 Dodge Caravan.  The great part was you'd never be able to see it once it was removed.  

They removed the driver's side taillight and fabricated a bracket that attached to the body behind the taillight.  It extended out in the space between the taillight and the back gate.  I believe they used some 1/8" or 3/16" steel for the bracket.  It still allowed good visibility of the brakelight (for you safety gurus) and the gate could be opened as normal.  

Its been my experience that using the inside lip of trunks and hoods is a good place to get a well grounded and solid mount, yet is also invisible to most anyone that I might sell the vehicle to.  I know that to me, and the majority of people I know, seeing a ballmount or even hole in a roof is a big bargaining chip when trying to talk a car seller down in price.  If I'm selling the car I'd rather not try to explain it.    

Mark
KC0HBM

Well said.  I think its great to have pride in acheiving the code requirements and advancing one's license, but too many look down on those who are happy with their current privilidges.

Not to stir up another huge pot of controversy, but the reason I have stayed no-code is I don't have a use for the code.  I would like to use 10 meters to chat with my friends a few states away, but thats all.  I have passed the written General exam easily, since I have my BS in Electrical Engineering.  I've also participated in several dozen contests, a few Field Days with my college club.  I really doubt that passing a 5wpm morse test makes me 'ready' or 'better suited' to operate on HF  

The truth of the matter is there are so many frequencies above 50Mhz, I have plenty to explore.  I only hope more hams stay "up here" and use the bands we have, because most modern communication services aren't trying to steal 40 meters (etc), they want 2Ghz and up!! (based on my research)

Cya on VHF!

Mark
KC0HBM

 

There are FCC regulations about the length/location for FRS antennas.  The reason you see the store radios with stubby attached antennas is because they are forced that way.  I can't remember the specific length, but I think the limit for FRS radio's is 3" or so.

Unfortunetly, I haven't had much experience playing around with GMRS so I'm not sure if similar limitations exist.  Assuming you an legally make your own whip antenna, my advice would be to get a SMA to BNC adaptor.  Then you can find dozens of BNC connectors that have a 'stationary' center pin.  BNC panel mount connectors are such a class of connection.  

The most basic approach would be to attach 1/4 wavelength of good conductor wire to the center conductor.  At 460Mhz the 1/4 wave wire would be around 16 cm.  Chances are you will create a better antenna because most HT antennas use helical designs. (I would make my antenna professor cringe to use the term "better" so loosely; in this context I mean the antenna will have higher gain)   Such antennas allow for the shorter lengths most operators prefer (less sticking into the gut)

Hopefully others here have more information about the service restrictions on antennas, since that needs to be your first consideration.

Mark
KC0HBM

If you are having such problems with the phone why not purchase another?  I would even suggest a "wired" phone (antiques that they are becoming), since they are not dependent on a RF link.  I can't imagine the cost of a new phone being any higher than moving your station mobile

I don't have many positive things to say about phones made by companies with "Bell" in them.  Southwestern Bell, BellSouth, etc... all junk in my opinion.  Personally I have found GE, Sony, and even Vtech cordless phones to perform better and not be so finicky about noise in general.

I hope this helps,

Mark
KC0HBM

"....landing officers radios begin to break up and he becomes unreadable. "

I know it may be hard to tell, but do you think the radio is transmitting but the audio is breaking up? (distorted)  Or is the audio okay but the transmitter is broken? (like someone randomly keying and un-keying the radio while talking)

You also mention that the interference begins when the helo is on the pad... does it actually have to be touching the pad or can it be just a few inches/feet above the pad for the interference to begin?  If the pad is conductive metal then prehaps there is a strange conducted RFI phenomenon going on here.  

Thats about all I can brainstorm for now, I hope it helps a bit.

Mark
KC0HBM

of course for full details you can go to sites like www.ilink.net or search Google for "ilink".  Here is the basics I know:

ILINK started using a Voice over IP software and windows.  The instability of that OS led to ILINK using Linux and a free open-source Voice over IP program called SpeakEasy.  There is some external hardware required for an ILINK setup, it does the following tasks:

- takes COS from radio to computer and provides computer means of keying radio (PTT)
- decodes the DTMF commands used to control the link
(It connects via LPT port)

The rest of the software just digitizes voice and streams it to another site or to a "refector", which simply repeats a single stream to many users.  

If you've ever used a program like Microsoft Netmeeting voice chat you're experiencing the core of ILINK functionality.

For more information I would really suggest checking out the ILINK homepage above.

Mark
KC0HBM

I worked for Garmin for a summer internship, so I got a chance to take home just about every unit they make to play around with.  The full line of eTrex's can supply serial data out, which is what is needed to interface to the D700.  You have to select which format you desire (NMEA) from the GPS menu system, but thats it.  

I purchased the power/data cable with my eTrex Summit.  The cable has a 12V cigarette lighter plug and a female DB9 connector for data.  I'm not familar with the DB9 gender on the Kenwood, so you may need a gender changer or null modem adaptor.

The basic eTrex (yellow) has an excellent receiver and you can't beat the price (~$100).  My Summit (brown) has a built in altimeter (more accurate than just using GPS triangulation for altitude) and electronic compass (so you dont have to be moving to determine direction).  Garmin makes eTrexs with higher res screens and lots of mapping abilities.  I chose to purchase the StreetPilot III instead because it has a nice color TFT display and also has autorouting and voice prompting for navigation.

I hope this helps,

Mark
KC0HBM

Well, I dont do any 10M mobile work yet but I can tell you that the cigarette lighter plan is probably not going to work.  100W is most likely going to be more current draw than a factory installed plug can handle.  The "nicer" of radios you get the more you need to worry about RFI and noise from your engine, so your best bet will be direct power leads from the battery (fused on both polarities).

If it were me, I'd take the single unit.  Seems like less to have to mess with getting set up, as well as less space for an install.

One more thing, you still should be able to do your quick vehicle-switch as long as you wire both vehicles with a good power connection and the same plug.

I hope this helps a bit,

Mark
KC0HBM

I believe my TinyTrakII documentation told me this:

set the path to RELAY,WIDE,WIDE

Its worked well for my interstate travels so far.


Mark
KC0HBM

The ADMS cable usually only makes one connection: to the data input of the radio.  My Yaesu VX5r also uses the 4 conductor plug.  The second "ring" from the tip is the data connector (from Yaesu's manual), and when I opened up my programming cable I verified only two wires are used by the circuitry to connect to the radio(DATA and GROUND).

APRS/TNC need access to audio and mic/PTT lines.  Basically your TNC "listens" to the audio from you radio and decodes data from what we hear as bursts of noise.  It can also "key" the radio and generate its own noise just like a human operator talking into a mic.  So you programming cable is going to be useless because it never connects to the audio/mic lines (these connections are the tip and third ring of the 4 conductor plug)

I dont know about damaging the TNC, but I doubt you will damage the radio if you did try.  the radio should ignore anything on its DATA connection unless its in clone mode.  Don't take my word for it, its best (and cheaper) to err on the side of caution!

Follow whatever instructions you may have received with the KPC or check out www.packetradio.com - they have alot of good interfacing information.

Mark
KC0HBM

I dont see a callsign for WD-40, I'm curious where you found it.  Personally I think he just likes to cause problems.

Just in case you were referrring to my Tech status, I do my contesting as a part of W0EEE, my school club.  We have plenty of generals and extras to act as station control

Mark
KC0HBM

http://www.fastq.com/~louvu/mobile.htm
http://www.fastq.com/~louvu/antenna.htm


The above links show a pretty nice mounting job in a Tundra.  Its definetly not mine, since I drive trucks (Ford) not toys

The biggest disadvantage to GMRS is its not a free service.  You spend the $$$ for the radios and then more $$$ for licenses.

I didn't mean to imply any old VHF radio will do MURS, i guess I was thinking more along the lines of more modern programmable business band radios.  

The other disadvantage to more powerful radios (besides cost) is size/weight.  I can't imagine it would be much fun to go skiing with a big radio on the belt