N8BMB on May 26, 2007    M    As one of the few 6m "guru's" ( as I have been referred to) in my area, you are right about this time of year.
I fabricate my own antennas for base use. I have not bought a commercially made antenna yet for my base. My first (of 6 I made) antenna for 6m was a 1/4 wave dipole. It worked very well. I then made a 1/2 wave dipole , but that was somewhat deaf. Then I made a rotateable dipole out of two 6m hamsticks that I was given, and it worked VERY well!!! Then I made a 6m longwire and worked 90% of my grid-squares with that one. I then made another 1/4 wave dipole for a canadian ham friend and then I just completed (last August) a 3 element Yagi and have not yet been able to give it a decent test.

My advice to you is to put together a 1/4 wave dipole and string it outside. You will fare very well, I think, with that antenna and I don't think you should have any problems with it.

===================

1/4 wave dipole?

    That's a new one on me.  If you are talking about 1/4 wave on each side, that's a "half wave" dipole.  A "quarter wave" dipole would NOT be resonant at 50 MHz, and a dipole with a 1/2 wave on each side would exhibit a high impedance and a horrible match to coax; THAT might be why what you describe as a "half wave" dipole didn't work for you.
----------

    Be that as it may, the traditional dipole is 1/2 wavelength overall, or 1/4 wave on each leg.  The formula is usually considered as Length (in feet)=468/Frequency (in MHz.)  That will be approximately 112 inches, or 66 inches each side.  (A half wave of conductive material, such as tubing or even wire will have a slightly shorter physical length than a halfwave in free space; the "468" incorporates a velocity factor of 0.95, or a physical length 95% of an electrical length in free space.)   Normal procedure is to make the legs a bit longer, and trim for resonance at the frequency most desired.  (Here in the U.S. for SSB/CW work, we use the low end; 50.125 MHz is the domestic SSB calling frequency; 50.110 is the DX [Intercontinental] calling frequency.)  So a frequency to choose might be 50.150 or 50.200 MHz, that will cover most of the weak signal operations.  Your area may have different frequency choices; check with local operators, or RSGB recommendations.)

    While a dipole WILL work, and make a reasonable match to coax, it's not ideal, especially if strung from a balcony:  it WILL exhibit directionality broadside toi the wires, and metal objects in the near vicinity will greatly affect the radiation pattern.
    Loops or squares are usually omnidirectional, and will have a better radiation pattern.
    A vertical is another possibility; while it WILL be "lousy" (GUARANTEED!) for local work on the weak signal modes, which are almost all using horizontal polarization, it will give passable performance on Sporadic E and other "enhanced propagation" modes, where polarization changes and becomes random due to unpredictable action of the atmosphere.
    Not knowing your exact situation, it's difficult to make a more specific recommendation.  Any antenna you can get out in the clear will be usable, but try whatever you can, and have fun!
   

Also, PARTICULARLY if you are using the amp in a mobile environment, the fuse(s) should be located AS CLOSE TO THE BATTERY TERMINALS as physically possible.  You DON'T want a short in the wiring to do anything more than blow the fuses.  Auto batteries have no short circuit protection as an AC powered supply would; the current they can supply to a short can easily start a fire.  And that's just as important for the wiring of a low power radio as it is for a high power amp; smaller gauge wire that shorts in a mobile installation (without proper fusing) can be even MORE likely to start a fire than wiring for an amp.  Proper fusing is essential from a safety standpoint, as well as for best performance of the equipment.

KC2PTA:

    Again, the ARRL Antenna Book is an excellent resource for both theory, AND practical construction projects.  And the CEBIK site has plenty of ideas and explanations; much, much more than we can provide here.  (Just don't waste ALL your time reading CEBIK's pages at once... it's tempting.)

    Good luck, and let us know how you are doing.  We WILL help if at all possible.

The analog meter requires a rather large hole, and may not fit into the enclosure...

    But you might not be satisfied with the digital meter you suggest.  Many meters (including the $10 wonder from Harbor) have an "auto-off" feature, and will power down if the input doesn't change for a period of time.  So after a few minutes, the display would go blank, and you would have to (usually) turn the switch to restore the display.  (That function is for those of us who forget to turn a meter off and saves the battery.)

 KB1LKR on May 26, 2007  
      Put another way: a Yagi of 3 or more elements (2 is also possible) have one (the longest) reflector element at the back, then the driven (feedline connected) element (possibly a flattened loop, but usually straight rods), tnen one or more (9 for an 11 element beam) director elements -- each an little shorter than the one before -- toward the front end.    
=================

    Actually, a 2 el. Yagi COULD have either a reflector (most common) OR a director...
     The driven element of a Yagi is ALWAYS the element connected to the feedline, but because some designs use a shortened driven element to allow a particular matching network, a director may or may not be shorter than the driven element, so you can't tell just by casual appearance if a 2 el. yagi has a director or reflector.

    That's NOT the issue here.  The antenna in question will have a single reflector mounted behind the driven element.  In this case, THAT end would point SOUTH if the rotator is properly aligned and set to point North.  The director end (most likely with each element slightly shorter than the element before it) will point NORTH.

    HINT: Be sure to provide plenty of slack, flexible coax at the antenna end of your system, to allow the antenna to rotate without undue stress or binding of the feedline.  If you are using some of the higher quality coax that uses a solid center conductor, you should use a short section of "flex" type cable (probably at least 6-8 feet) so the coax doesn't get tangled or wrapped around your mast.  If you haven't bought coax yet, it's usually worth a few extra $ to get the "flex" version of the type you choose; it will use a stranded center conductor, rather than a rigid solid wire.  There are flex versions of LMR-400, Belden 9913, and others.

Thanks for the update.  I hope a conviction IS obtained, given the circumstances.  And then the FCC WILL take action (as they said, after a conviction.)  Then again, the crooks wouldn't be able to operate while incarcerated, anyway!

That's about right.  The 12-14 hour charge for the NiCd cells was probably at a C/10 rate, (600mA/10=60 mA charge rate.) The charger probably won't put out moch more than the 60 mA required.  Thus, 2100mAH/60 mA =~ 35 hours; add to that the extra 20% needed to completely charge (12-14 hrs. vs. 10 Hours for a C/10 rate) it will take approximately 42-48 hours to completely charge your batteries.  (More battery capacity means longer charge time.  No way around it.  If you can find a rapid charger for the unit, that would be a better solution.)

Unless you are a licensed Amateur, it is illegal to transmit on the Amateur frequencies OR the "CB" frequencies in your country.

    You are asking us to recommend instructions to allow illegal use, when ANY use of a 70 cm H-T appears to be illegal for you.
    Don't hold your breath...

   Buy an appropriate H-T for your "CB" service and get licensed if that's what is required, but don't expect us to condone or assist illegal operation.

Update:

    The original SCR is actually a type 2N681; rated 25 Volts@25 Amperes.  (The schematic isn't the best possible copy, and if you have a scan or copy of a copy, the part numbers can be pretty blurred.)

    The output from the rectifier/filter cap should be about 29 Volts no load, 25 Volts full load.  There is a MOV (Varistor) across the filter capacitor rated 39 Volts, 600 "Watts."
   

    While troubleshooting, you may want to disconnect the SCR to eliminate that (overvoltage sensing) part of the circuit from preventing proper operation.  Just be sure it's reconnected before connecting the supply to a radio.
 

AA4PB on May 23, 2007       If I cut off one side of all the elements on my yagi does that make it an SSB antenna? :-)
 ====

    Actually, you have to split each element in half lengthwise.  Then you use just the upper half for frequencies above 9 MHz, and the lower half of the elements below 9 MHz.

You'll have to take it one step at a time, and do some unsoldering.
    First, unplug the unit.  (DUH!)  short the big caps with a resistor; 100 Ohms or so should be good; just enough to discharge the cap(s) quickly but safely.
    Disconnect the PC board from the Caps; check the rectifiers with an Ohmmeter.  (Some supplies used stud mount rectifiers, while some apparently used half of a square bridge module.)  Then fire up the supply and see if you get ~25 VDC at the filter cap.  (I won't have the schematic in hand until tomorrow, so the voltages are ballpark figures.)  If that's OK, then (again, unplug the unit.)  Check the active devices (diodes, transistors) and plan on replacing the 723 regulator, the SCR, and possibly some of the diodes, maybe even one or more of the pass transistors.

    Even if the part numbers aren't exactly the same, the circuit itself will be similar enough that you can use the schematic to troubleshoot.  Don't bother calling Astron; you will know which version of the supply you have when you open it up.  Parts CAN be substituted; you may need to do a little bit of searching, but none of the parts are so unique or unavailable that you can't find replacements.  There are many SCR's, for instance, that can be used; you can either ask Astron for a replacement number, or pick one out yourself.  Just match the current capabilities, and trigger current; if the voltage is higher than the original, it will still work.
    The only REAL unique part is the 723 regulator, but those are common enough, and made by several manufacturers.  Mouser is a good source for parts; probably less than Astron.  The source of the parts isn't important, as long as they have similar or better ratings.


Remove the 723, but don't toss it just yet.  Check the various resisrors for drastic value changes.

    It will take some time, but unless the power transformer (most expensive part of the supply) is toast, the supply is repairable and worth repairing.

    Keep us informed, but don't connect any equipment until you're sure it's working properly.  (a good test load is an automobile headlamp; with both high and low beam working, it will draw 5-10 amps.  Cheaper than blowing out a radio...)

K4JC on May 22, 2007    
    147.300, +600 offset, 103.5 tone. Call sign is WD4WDW. I believe if you contact a member of the club you can get a special QSL card...but don't quote me on that!
=====================

    Don't hold your breath getting a Mickey Mouse QSL card.  Several years ago, I worked one of the California  D.E.A.R.S. special event stations.  I've sent a total of 4 SASE's, with the QSO info and their Contact reference number.  Not a reply to ANY of them; not even a return of the SASE.  Somebody probably cut out the stamps for their own use.  GREAT PUBLIC RELATIONS, DizzyCorp!  
    If an organization sponsors and advertises a special event (especially if the sponsoring organization is a "for profit" business) they should have the courtesy to send QSL cards they promise.  (And a corp. as big as Dizzy shouldn't even require a SASE.)

You should be OK with the ES-35.  As long as you don't try to transmit on both radios (at least, not at anywhere near full power!) at the same time, you should be fine.  Even while transmitting, unless you are operating 100 Watts on either radio in a 100% duty cycle mode (RTTY, FM) you shouldn't be taxing the supply; on SSB, you would only draw full current on voice peaks, so the average draw would be less than the maximum rating for the RS-35.
    If you DID mistakenly transmit with both radios at the same time, the supply would go into current limit mode, and neither radio would work.  You'd probably have to shut both off to get the supply to get back to normal.  (I'm not quite sure how it would work; I've never pushed my RS-35 that far...)
    If you also run a number of accessories from the supply, however you may be getting near the limit of the supply when you transmit, so another RS-35 supply might not be a bad idea.  (Or a smaller supply for accessories:  I use a 4 Amp Astron supply for things like a digital clock, TNC, tuner and SWR bridge pilot lights, etc.) Better get that letter in to Santa Claus early...

BTW, it would be an excellent idea to get a copy of the ARRL Antenna Book, and also the RSGB VUH/UHF Manual.
    Both are excellent references both to antenna theory, and a treasure trove of construction ideas and projects, especially for the bands for which you are interested.  All hams should have at least the Antenna Book, second only to the Handbook.  Good luck.

No offense, but the answers aren't going to change, no matter how many times you ask the question.  Asking the same basic question twice in one day IS a bit silly, really.  Such antics are less likely to get repsonses in the future, whether it's to your question about "SSB antennas" or any other topic.