Correct.  I also note from the schematic that the power source of for the LED's is direct from the battery.  LED's being nonlinear devices can see a huge swing in current for a small change in input voltage.  The battery can exhibit probably a volt or more difference from full charge to dead.  The series resistor would have to be chosen for the highest expected voltage.

Another enemy of LED life is heat.  Even if you run an LED within current spec, if you can't adequately heat sink the die it will burn out.  You'd have to verify if the PCB and radio case allow for adequate thermal conduction and dissipation.

I'm going to bet that not a lot of reliability engineering went into this "feature".  It was anticipated one might use this for a few seconds to find your keys or whatever, not serve as general illumination.  A similar situation exists for smartphones.  You can get apps that turn the camera flash LED on continuously, turning your phone into a $500 flashlight.  I wonder how many people have burned out the flash LED's in their phones doing that. 

LED lights are ubiquitous anymore so if a continuous duty light is what you're after, just buy a dedicated light for that.  If the LED light in the radio is of prime importance, crunch the power and thermal numbers for what the radio can accommodate and pick an SMD LED that will best fit.  That would be a big project for something that could be solved as simply as buying a $3 AAA flashlight at Harbor Freight.



You'd be surprised.  I've done a bit of work prototyping LED light assemblies for a national lighting company.  I've built some arrays using 5x5mm LED's that are so bright you don't want to accidentally look at them - they're like looking at the sun.  Put 144 of them on a 5" disc and you've got something as bright as a streetlight - which is exactly what they have in mind.  You still need to get the heat out though no matter how efficient they may be.  It's especially challenging when you have these tiny packages that you need to get several watts of heat out of, then multiply that for an array.  I would bet that the LED in the HT may be nominally within the current rating but they didn't accommodate the thermal dissipation for worst case.


Mark K5LXP
Albuquerque, NM

There is a strategy to what antennas you use for a contest like this.

Using an 80M dipole on higher bands means lobes and nulls.  If the lobes end up over the ocean and the nulls over population centers, this choice could be a decided disadvantage.  The pattern will change as you change bands, so what might be a good antenna orientation for one band may not be for another.

Another disadvantage is having to use a tuner.  It's just one more thing to take along, hook up, mess with, and potentially fail for the duration of the event.  I've been with clubs that would put up two beams and an A/B switch to avoid having to wait for a rotator to swing a single beam around.  Every 10 seconds you futz with a tuner is one less Q in the log.

Of course if this is just a casual operation you can run whatever you like.  Just pointing out that an "all band" antenna choice like this requires more thought than just the bands it "covers" if you expect to have any edge over the thousands of ops who take this seriously.


Mark K5LXP
Albuquerque, NM

Can't hurt, but an ugly balun is often not as effective as a ferrite one. 

http://www.karinya.net/g3txq/chokes/


It's not what you're transmitting, it's what the affected equipment is detecting.  How sensitive something can be to RF energy is dependent not only on the intensity of RF but also how well the item is shielded and isolated, and how the end user connected it.



I wouldn't.  I suspect if it's ever a problem you'll find out about it.



That just means you have especially sensitive speakers.  I have several sets of amplified speakers on PC's and a surround speaker set on my TV.  I've never bothered them.



That's a win-win for you.



Technically it's up to them to come up with and pay for any remedy.  You can be a nice guy and do that but that's a form of implied guilt.  First thing I do is point to the Part 15 notice that's on just about everything these days.  From there we can work on an amicable solution.


Any time you have an antenna that close to or inside a structure, the field strength will be that much higher plus there's more opportunity for energy to couple into power and signal wiring.


Mark K5LXP
Albuquerque, NM

Could be anything.  On 6M I pick up my cordless drill charger in the garage.  If it's there 24/7 it's something local, because you know the band isn't open that much.

Mark K5LXP
Albuquerque, NM

The radio doesn't determine the range, the antenna and antenna location will.

The issues of radio licensing and certifications comes up here in Albuquerque during our annual hot air balloon fiesta where pilots and radio equipment come in from all over the world.  Bottom line is that technically it's not legal to use 2-way FM commercial radios for flight operations.  I recall the solution was to use aircraft radios, which have channels dedicated for the type of use you're proposing.  I think the aircraft radio certification process is less border-centric and I don't think the FCC requires a license anymore.  Not sure about Mexico, you'd have to check.  Even the guys that hang glide from our mountain are required to use aircraft radios (and oxygen tanks - they soar well above 10,000ft).

There are numerous aircraft HT's for a reasonable amount of money, so if this solves the problem that'd be the way I'd go.

Mark K5LXP
Albuquerque, NM

Exactly.  Except they should originate at the feedpoint, in this case the bottom of the downspout.



No.  They won't be resonant so the goal would be as many as you can, as long as you can, in any direction you can.


Mark K5LXP
Albuquerque, NM

I did a very similar setup with an Alinco HT.  I lined the inside with copper tape to help as a 2M groundplane and also put in a pack of 8 NiMH batteries.  The GPS puck can stay inside or be used externally like yours.  With the tinytrack controlling the radio power I can get over 24 hours of operation from the internal pack or it can run from external DC.  There's also room in the box to store a palm pilot and serial cable I can use to reprogram the tinytrack in the field.  I like the form factor of that pelican case, it makes a great sturdy but still portable/deployable APRS box.  I have a single external on/off switch outside so once it's set up I can just hit the switch and off it goes.

Mark K5LXP
Albuquerque, NM

Practically speaking, what would you do with an FM-only 10 and 6M radio? 

The V/U models would offer a bit more because they'll work fine for most local communications.  With SP RSS and software for the X9000 heads you can make up a single head V/U setup.  But it's a lot of messing around.  I think if you want to play with the circle-M stuff I'd go with spectras and leave the syntor stuff behind. 


Mark K5LXP
Albuquerque, NM

This doesn't have to be 2/0 cable in armored conduit anchored on concrete pillars.  Twenty-something gauge black or brown insulated wire tucked in cracks and crevices or tamped under the surface of the soil would work fine and would be 100% invisible.  A few of those, while not optimum, would "work". 


So why don't you take better measures to hide it? 

On one hand I'm sympathetic to your plight and an would like to see you achieve some degree of success.  On the other, you need to be willing to take a bit of risk and assume the "forgiveness is easier than permission" stance.  If you're so paranoid about getting "caught" laying a piece of wire on the ground where it cannot be seen by nor affects absolutely anyone, then perhaps stamp collecting might be a safer pastime.  I speak from a position of having installed antennas and feedline in some very restrictive situations, from apartments to military barracks.  RF obeys the laws of physics, not rules of HOA's.

There's also the notion of obtaining express permission.  A well drafted proposal and a few friendly visits to the powers that be may net you much more than you could do by stealth.



A balanced antenna as KE3WD suggests.  If you can't balance something above ground you need to isolate it from ground with radials.  How these methods are physically effected are where you need to get creative.  Hide it, repurpose existing structures (like the gutter), or hide in plain sight (put up a "bird house", "flag pole" or "flower trellis"). 


Mark K5LXP
Albuquerque, NM

A ground rod is not a radial.  Wires along the ground are radials.  The more you have the more efficient your antenna will be.  Of course in this situation optimum may not be possible.  If you're going to run the downspout like this, you'll be better off with whatever radials you can run however long you can make them.

Mark K5LXP
Albuquerque, NM

I agree.  The scotchbrite/steel wool treatment is for when the antenna has gone beyond the regular dull gray patina and you're refurbishing it to reinstall or sell.  Most antennas I refurbish like this are hamfest specials I pick up cheap or free.  Often they've spent a period of time laying on the ground and are pretty nasty.  Polishing accomplishes two things.  It removes all the dirt and corrosion present and makes the element look almost new.  Refurbishing an antenna like this is a lot of work but when you're done you have an antenna you will have no problem selling or will be proud to install on the tower.


The conductive and no-ox pastes perform a couple functions.  One is to promote conduction through both the metal particles and by cutting through the oxide layer, the other is by displacing air and moisture an inhibiting corrosion.

For telescoping joint connections I use automotive wheel bearing grease.  The No-Al-Ox and copper pastes usually recommended are OK but they don't seem to hold up as well when exposed to the outdoor elements (at least where I live).  The primary beneficial function of these treatments is to keep moisture out, and I've found the bearing grease stays in the joint even in the NM sun.  Just about anything on the joints is better than nothing.  Otherwise you end up with forever seized together sections.


Mark K5LXP
Albuquerque, NM

Don't tell Mosley that.  They specifically recommend using 000 or 0000 steel wool for aluminum elements.  I like the degree of polish you get with steel wool vs scotchbrite.

Technically you can't use this technique on aircraft.  Antennas aren't aircraft. 

Mark K5LXP
Albuquerque, NM

Ham radio operators aren't the only ones that want a "complete" unit of [whatever] even when buying well used equipment.

If you want to see the value of an original box, look at collectible toys.


Mark K5LXP
Albuquerque, NM

WX7G is right, this is fundamental overload.

One other thing you can try is an unun (choke balun) on your dipole.  If you've got any common mode maybe these will help reduce some of the energy floating about.

It's possible a combination of cures will be reguired - choke balun, ferrites, bypassing.  Using the technique WX7G describes will help lead you to what method is having the most beneficial effect.

Mark K5LXP
Albuquerque, NM

The proper circuit would be called an audio pad.  Just like an attenuator for RF.

You could go through all sorts of machinations computing source and load Z with the various levels you'd encounter but it's simpler to just play with it empirically and come up with a fixed ratio that gives you the levels you want going into the laptop at nominal speaker levels.  One I'd start with is a series R of say 1000 ohms and a shunt R of 100 ohms.  You could also substitute a potentiometer and allow you adjustment on the fly.

http://www.uneeda-audio.com/pads/

I just went through this dubbing some old cassette tapes.  I was able to fit the resistors right into the 1/8" stereo mic jack of my laptop.

Mark K5LXP
Albuquerque, NM