In my days at a USAF base in NY, one of the bosses had his two-meter rig on the credenza behind his desk.  I work at a base in MA and carry my handheld to the office.  I have used it in the parking lot and no one has said a word.  A lot of hams work here and they transmit at lunch time or sIgn up to the repeater to check on traffic before leaving.  No problems there.

However, if the base has active munitions, etc., the policy is to shut everything that transmits off.  Signs are always posted in those areas.  For secure areas, you do not bring anything with RF or storage devices in, period.  You have to check them at the door.  Advisories are also prominently displayed at the front door.

Transmitting from the parking lot?  Don't sweat it.

73 DE Bert @ KA2UUP

 

Yes, I guess I know about grounds after doing 25 years of communications work for the DoD and the Army as an electronics engineer.  Can't help it if some if us sound like perfectionists and have seen the damage that can be done first hand when things are not grounded, bonded and shielded per the NEC Code and MIL standards.

Have a nice day!!!!!

What I have at my house is a copper wire tied to the antenna boom, the mast, tower and then into the gorund rods which are all bonded to the service entrance ground.  Coax cables are connected to arrestors bonded to a copper plate which is enclosed with an outdoor plastic cover, the plate also bonded to the ground system. Never have had a problem with the system.

WB4JZY:

"while the components of your rig near the antenna ground remain near 0 volts. This 1000 volt difference in the first microsecond of the spike across your rig's components is what causes the current to flow through your rig's components and burn them out."

Yes, that is the right answer.  However, what is the difference between this answer and the ones that I, and a number of others here in the forum gave to you about "differences in potential?"  1000 V, 500 V, 1 V...it does not matter.  A difference in potential is a difference in potential, no matter how you look at it.  What you are trying to do with bonding all the grounds together is to MINIMIZE that potential.

I also find it insulting that you are telling someone to take a "chill pill" because your call sign is not in the ULS database.  It is this type of behavior that is keeping some of us in helping REAL amateur radio operators or asking questions, for that matter!

"...Why would the current choose the path through the high impedance components rather than the big metal chassis and the fat green ground wire?"

Because, like the previous poster says, all the components are tied to ground in the chasis, and the chasis is tied to the safety ground, etc.

Let's put it this way.  A lightning strike carries what, a million amps of direct current?  That is a lot of current that requires some serious carrying capacity in terms of copper.  There are no electronic components in a modern radio that can carry that current.  As a matter of fact, it does not matter what the impedances of the components in the radio are, they are no match for that type of current.  In short, it will VAPORIZE them if the strike is big enough.

The idea of bonding both grounds (entrance and electrical service grounds) is to reduce the potential difference during a strike.  When lighting strikes the powerline or the antenna (see W8JI's aforementioned drawing), the idea is to have all grounds go up and down in potential at the same time.  Current flows because of a difference in potential.  Minimum potential equals minimum current through the equipment during a strike.

Look at the National Electic Code.  It is required to have the grounds bonded.  People that don't do it are stting up themselves to have their stations as test subjects on what NOT to do when lightning strikes!

Someone, HELP!!!!!!  I cannot explain this any better.

Bert @ KA2UUP.

W8JI says to take a look at the diagram.  That is the answer.  Interpretation:

You have your termination not properly bonded to the building electrical service ground,  but your equipment's green wire (the third prong on the power cord) is connected at the power receptacle to the building electrical service ground.

Now here is the deal.  Not only will you have a difference in potential caused by the strike between the two grounds which will cause a current to flow along the ground, but you have to remember that that curent flows through the path of least resistance.  In this case, the path of least resistance is that third, or ground equipment wire that is there to provide a safety ground.  We used to have a saying in electrical engineering school:  "In case of a failure of a live wire touching the metal cover of any equipment, you want to send that current back to where it came from."  Therefore, the green wire of your equipment is connected to the electrical entrance ground.  Still with me?

The board components in your equipment are grounded to the chasis as a common voltage reference, which is grounded to the safety ground, including the metal cover.

Which path is the current going to take?  The path of least resistance, which is your ground wire to the shack entrance, thorugh the gorund connections inside your equipment, thorugh the green wire to the electrical service ground.  What are the connections made up inside your equipment?  Copper, which is highly conductive.  I don't even want to mention the internal flashovers, etc. that would occur between components.

Result?  FRIED EQUIPMENT?

I hope that answered your question and dispelled any doubts.

Anyone, feel free to correct this post or add to it.

73 and be safe, DE KA2UUP

My MA5B is at 30 feet on a Rohn 25 tower and works well.  However, about 6 years ago I had it in a temporary installation on an extensible mast at about 20 feet and it did adequate work but it was heavy as hell to bring down and put up when servicing or checking the mast out to see how it was handling the weight of the antenna and rotator.

If space is a problem I would suggest a MFJ-1798. Mine has been up for 8 years and offers 2-80 meters.  I have never used the 2 meter portion, but can tell you that the 10-17-20-40 and 80 work well.  As always, this is a compromise vertical (which one isn't).

Good luck DE Bert @ KA2UUP

Check ANA Instruments at http://www.anainstruments.com/, (540)775-9375.  I think that is in VA.  They sell the things new and they may be able to supply you a copy of the manual, probably for a modicum price.  I have checked all other databases like mods.uk, RigPix and BAMA with no success.

Good luck and 73 DE Bert @ KA2UUP

Don't you just love it when people make accusations before knowing the facts or look for stuff that is not in the original posts?  What have we come too!!!!

Have you tried the D-Link card?  That is what I used when I am out of range from the router in my house.  Works well.

73 DE Bert @ KA2UUP.

Yes, it should be tied to the electrical entrance ground.  As the above gentleman says, what you want to do is to eliminate the potential differences between grounds.  When both grounds are tied together, both of them will go up and down in the event of a lightning strike and no currents (theoratically) caused by the difference in potential between the two grounds will find their way through other paths, like equipment or, God forbid, someone else!

Best way to do it (this is from experience) is to bury ground rods every 16 feet, assuming they are 8-foot rods, and tie/bond them together on the path to the house entrance ground.  That would be the safest way.

Good luck DE Bert @ KA2UUP

Mike,

The picture gives you the impression that the antenna is at the 45 degree angle.  But that is not the way to install a Yagi.  The MA5B is installed with the elecments parallel to the ground.

73 DE Bert @ KA2UUP

MMSSTV, the latest version.

73 DE Bert @ KA2UUP

I have one.  It is not a super duper antenna like one of Cushcraft Boomers, etc. but it has worked well for me for about 6 and 1/2 years.  I have mine mounted on a Yaesu 450 rotator on top of a Rohn 25 tower at 30 feet.  What my MFJ-1798 vertical cannot pick up, this antenna will.

Some caveats:

1)  Read the directions carefully. The capacitance hats (the little rods forming the Xs at the ends of each element) have to be oriented as they say in the instructions to ensure proper SWR readings.  Also, be sure to install the traps with the drain holes down to avoid water pooling on them. Better yet, sealing the joint between the traps and elements with some good electrical tape is an excellent idea.  That way you avoid water getting into the joints in the first place.

2)  Some users have complained that their elements windmill, or rotate, out of alignment.  This will happen if the elements are not tightened properly or if the main boom was not "notched" properly to allow the muffler strap to tighten.  The fix is simple:  just drill and put a screw through.

3)  While the manual gives some measurements to ensure that the antenna is tuned properly on 20 meters (those are the end pieces for the two active elements), mine ended up being about 100 kHz above the frequency I wanted to end up.  I strongly recommend not to follow the measurements and, instead, use an antenna analyzer or an SWR meter on the ground before you raise the antenna up permanently to tune the antenna properly in the area of the band you want to operate in.  An SWR of 2:1 accross the entire 20 meter band should be no problem if you tune right at the band's halfway point.

Remember, all multibanders are compromise antennas.  This one works well for the price and the small size.

I hope this review helps in you decision.

73 DE Bert @ KA2UUP    

My AL-811H has been running with Svetlana 572Bs for 7 years.  The benefit?  On those careless moments when you are tired and so something stupid, the tubes will not blow up.  Increased life of the amp?  Definitely!!!!!  As you say, you will not get more power.  You may be able to sneak out about 20 W more which is insignificant on the far end S-meter.

Is it worth the money? I will not go into the argument here like others do.  For me it was worth it.  There is a post by Tom, W8JI, who designed the AL-811H and other amps for Ameritron where he says that he designed the AL811H within certain cost constraints.  That cost constraint is in the tubes used.  If you can afford it, change the 811As for 572Bs.  I am glad I did!!!

73 DE Bert @ KA2UUP  

My experience is similar to VK1OD.  Based on readings using a Kenwood SM-220 to ensure linearity, 600-650 W on CW and 700-750 W on SSB is a honest measurement.  Because of the tolerance to higher duty cycles of the 572Bs, you may be able to squeeze about 20 W more, but that is about it.

It is an excellent amp, though, for the money and can tolereate the abuse of a rooky operator.

73 DE Bert @ KA2UUP