[FADCA] Tested Melbourne FPAC this morning

Fri, 31 Oct 2003 10:32:52 -0500

I looked at the 70cm link a little today.  Here are some observations:

Vero:

 Signal strength from Vero is 'funny'.  It will vary between S0  (no LED
bars lit)  to S4 (4 LED bars lit)  IN A SINGLE TRANSMISSION.  He goes up and
down that much, that quickly.

Could be normal,  could be loose connector on antenna, could be antenna
pointing,  could be a combination of them.    Vero used to have a solid
signal up here for me (comet vertical up 40 feet - omni).   

That kind of signal strength variation looks 'funny' to me.

That not-withstanding.   MLB seems to handle it OK, BUT, there is a funny on
our side too, perhaps.

I am not sure of the packet parameter name, but it appears that MLB 'acks'
the vero transmission way too quickly.  There needs to be more of a delay
between receiving a packet and responding on our part.   From my slow S
meter, it almost looks like mlb is stepping on vero -- this can't be true,
but indicates how quickly (how small a value the param is set to) the ack
is.

I am watching the vero 70cm comm. At the same time as the 2 meter lan comm.
On a kenwood TMV7a which has dual display, dual s-meter, so I can see the my
station (another radio -yeasu) and the switch talk back and forth, at the
same time watch the switch and vero talk back and forth.    So the times
between RX and acks are subjective, I can see the relative differences in
behaviour between the two sides.

2 meter side is very solid.   70cm output level seems very solid on our
side.

Again,  it appears -- I stress "appears" -- that perhaps vero power or
antenna may have some thing that needs work.  And it appears we may want to
change the time between rx and ack to be a little longer.

As for 220 -- this is why the switch has been 'down' the last year -- 220
has been a total flake -- and it has been because the 220 side only
occasionally transmits.   Whether this is due to the 220 radio, or the TNC
-- is anybody's guess,  but the 220 side had a problem to begin with, and it
looks like it went with it to the new site.

If you have a 220 radio and another tiny-2  -  I would marry them up and
swap them out with the site,  that ought to take care of that.

As for the 70cm side,  just tweaking the ack response time, may beef up our
link to them.  Then vero can check out their antenna whenever.

(the stats on vero's end shows a lot of retries for each transmission  -- I
would request a 'T" over and over and watch the response, plus look at the
numbers they were giving me -- they were racking of the re-trans on their
side)

Cheers

rick

-----Original Message-----
From: [email protected] [mailto:[email protected]] On
Behalf Of bud thompson
Sent: Friday, October 31, 2003 8:58 AM
To: [email protected]; Andy Leeds; Bill Sinbine; Charlie Crook; Don
Winn; George Fundis; Ken Johnson; Kenneth Hendrickson; Mailman; Rick
Muething
Subject: [FADCA] Tested Melbourne FPAC this morning

Deltona
Friday Oct 31 0900E

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:

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.

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. 

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.

Here is what I conclude from my testing this morning:

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!)

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.

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.  

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.

Once you have time and are ready to do some investigations, here are some
things to check out.

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!  

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.  

            Assuming no DCD board - Now turn the volume control clear off.  

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.

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.

          If the TNC has a DCD board but the TNC RX audio plugs into the
speaker output of the radio - 

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. 

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!

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

You are getting close for a fact.  Now we look for that cigar!

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.

On Saturday I'll be traveling to Umatilla for the hamfest. I'll have my cell
phone with me. 

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.

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.

Let me know your pleasure.

bud N0IA
386 574 4124
cell phone 386 956 0386

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