[FADCA] Tested Melbourne FPAC this morning

bud thompson [email protected]
Fri, 31 Oct 2003 08:57:45 -0500


Deltona
Friday Oct 31 0900E
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Eric: - The Melbourne switch looks pretty good from here - Very close - =
now for the cigar!

I've listed some comments and suggestions later in this note:
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The Orlando FPAC 220 port is back on line.  60 watts out to a vertical =
antenna at 82 ft agl, still  located at my QTH in Deltona.
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In the past, it could work Cocoa N4LEM-2 / #COA during hours of =
darkness, but if memory serves, not until late in the night through =
sunrise, perhaps a tad beyond.  As late as 2000 hrs local last night I =
could not raise #COA.=20
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This morning the 220 link between Orlando FPAC and #COA was good. I =
started testing at 0530. By 0615 the link was not available and dawn had =
broken.  Later it worked fair at 0745 in full sunlight and I could still =
connect at 0845, but it was not solid.  I'll check it during the day =
today.
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Here is what I conclude from my testing this morning:
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1. The 2M LAN port on 145.09 is most likely working extremely well.  It =
works the N4LEM-1 / COA1 node at Cocoa FB, and hears a lot of stations =
on 145.09 (maybe too many!)
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2.  The 220 port at W4MLB is hearing #COA but is not heard by  #COA - =
Indicating  the W4MLB transmitter has low power, or the deviation is not =
set properly, or there is no DCD board in that TNC and the squelch is =
open or too loose. (If the latter case the radio could not transmit at =
all!)  If memory serves, this 'hearing but not being heard' has been an =
off/again on/again problem with this port.  My guess is it is not =
serious, only a matter of adjustments.
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3.  The UHF port is hearing Vero (I can't tell how well, but likely =
okay), but communication is not working.  W4RP reports the same on his =
tests direct on UHF with W4MLB.  The problem is likey at W4MLB.  I have =
a note into Rick to see if he can give us some ideas.  If the only =
connection between the TNC and the radio is through the front panel =
microphone connector, the problem could be receiver audio level/squelch =
if that TNC doesn't have a DCD board.  However, I'm almost certain most =
of those TNCs do have the DCD board.  If the TNC derives RX audio from =
the speaker jack in the rear of the radio, the problem is likely =
improper volume control setting on the front panel of the radio.  The =
problem might be TX deviation, but deviation was set on all those =
radios/mated TNCs in W. Palm Beach a year ago. =20
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I don't see anything else requiring any attention at this time. The =
routing I had been concerned about seems to be okay, but I'd still like =
to examine copies of those files mentioned earlier just to be certain.
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Once you have time and are ready to do some investigations, here are =
some things to check out.
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A.  On each radio, check the power output and VSWR.  In general, you'll =
likely have to have each radio running max power (25-40w depending on =
the model number).  Each of those radios has a LOW/HIGH power level.  I =
suggest running as much power on 2M as possible up to 60W.  That said, =
we may ultimately need to tone that down if the site is too good! =20
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B. Check this on each radio - With antenna connected.  Turn the squelch =
full counter clockwise (off) and look at the DCD LED on that TNC. If the =
DCD stays unlit, that TNC has a DCD board.  If the DCD LED comes ON when =
the squelch is OFF, that TNC does not have a DCD board. =20

            Assuming no DCD board - Now turn the volume control clear =
off. =20
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B1.  If the DCD LED DOES NOT TURN OFF the volume control has no effect =
on the TNC - make the following adjustment: Advance the squelch control =
until the DCD LED turns OFF, then advance the squelch about another 10 =
degrees or a little less.  The idea is to squelch off the DCD in the =
absence of an incoming signal but have the squelch tight enough the DCD =
does not turn ON with noise spikes.  However, increasing the squelch too =
tight reduces the effective sensitivity of the receiver for packet =
signals.
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B2.  If the DCD LED TURNS OFF, the volume control must be set before the =
squelch is set.  Make this adjustment:  With the squelch OFF, turn the =
volume all the way down and the DCD LED should be OFF.  Advance the =
volume until the DCD comes on solid (on receiver noise), and then =
advance it about another 10-15 degrees of rotation - not much.  Now, =
advance the squelch as in B1.
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          If the TNC has a DCD board but the TNC RX audio plugs into the =
speaker output of the radio -=20

B3.  Turn the squelch clear off (DCD should not light).  Set the volume =
control at about 10 o'clock.  The DCD should not come on except when =
there is a packet signal.

Now we have knowledge of transmitter power output and a good feeling the =
volume/squelch adjustments are nominal.  The only things we don't know =
are: transmitter deviation level and receiver sensitivity.=20
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C.  Using the console, try to connect to a packet station on each radio =
port.  You can use try WA4ET (DXcluster) or KN6KB on 145.09, W4OT-8 (or =
W4OT-2 if the Vero BBS is working) on UHF, and #COA on 220.  In each =
case, look at the S-meter on the radio when the target station is TX to =
get an idea of how much signal is available.  If you are on WA4ET, KN6KB =
or any BBS, or W4OT-8, just send H for help, and the station will send =
you a bunch of stuff.  All your transmitter will do is acknowledge back =
a short transmission once in a while.  If all is working well, the =
exchanges should be smooth without retries.  Data should flow onto the =
consol screen from the other station in a regular manner.  If your =
target station is a keyboard w/o anyone there, just hit enter and see if =
that station returns an acknowledgment transmission.  If every time you =
hit enter you get a return, all is well!
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D.  The DOS clock needs to be set for proper date and time of day. When =
I was messing around between 0530-0600 on October 31, the date/time =
stamp was Current Date:  10/30/2003-10:42:59
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You are getting close for a fact.  Now we look for that cigar!
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We have house guests back, but I'll be here most of the time today =
(Friday) I'll have my cell phone with me while out.  Call if you need =
anything.
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On Saturday I'll be traveling to Umatilla for the hamfest. I'll have my =
cell phone with me.=20
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Do you want Charlie and me to come and help out on Sunday?  If Bill =
N4XEO can come up you won't need Charlie and me.  It is your call and we =
are as available as your asking.
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I have a 220 and a UHF radio that could be tried there if it appears the =
radio is the problem on those ports.  I can also bring a Tiny II just in =
case.
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Let me know your pleasure.
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bud N0IA
386 574 4124
cell phone 386 956 0386

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