Thursday, April 13, 2006
PAC-12 antenna experience
I assembled the PAC-12 and laid it out in about 5 minutes. The longest
part was putting out the radials.
I then dialed in the multi-band coil for 40m using an MFJ-296 antenna
analyzer. I was pretty much able to get the SWR down to 1.0 or 1.1 on
the coil's "sweet spot" and was pretty much able to keep the SWR down
below 2.0 across the band.
The PAC-12 was attached to a Yaesu FT-817 running on its internal
battery pack and with the stock microphone. It was on "high" power. A
whopping 2.5 watts. The battery wasn't fully charged beforehand but it
should have been between 2/3 and 1/2 full when I started.
I tested the antenna by checking into the noon time net on 7.2685 MHz.
The network control station was coming in 5xS8. Some of the other
stations we S9+. A San Francisco station was about S2.
The outbound signal sure wasn't breaking any pile-ups but they were
eventually able to get my call. I'm guessing I was about 3x3. The net
control then tried to get me in contact with Craig, AE6RR. He was mobile
someplace in the Mountain View/Sunnyvale area. I heard Craig 5xS8. Craig
was unable to hear me. I'm betting NVIS was working but the signal was
too weak for local groundwave.
My impression is that the PAC-12 was doing better than the inverted-L
end-fed 1/2 wave strung in the trees that I normally use. Of course it
was MUCH better than the (snork) "Miracle" whip. (The miracle is that I
suspended disbelief to shell out $90 for it.) I still think that the
NVIS folded dipole is the "best" of the antennas we've tried.
I then tuned the PAC-12 up on 20m. It was about 1.5 at the "sweet spot"
and 2.0 at one end and about 2.2 at the other. Since the radio's battery
had petered out I just tuned it using the analyzer. We'll need to leave
the operating to another day.
The PAC-12 came apart about as fast as it went up. The longest part was
coiling the radials.
I also quickly tested the Palm Paddles, but didn't expect anybody to
answer my short CQ at 2.5W on 40m. They worked, that's all I was
expecting to find out.
My biggest lesson learned is that the FT-817 internal battery pack
really isn't the way to go. It doesn't hold up very long and limits the
output to 2.5W more or less. The radio goes to 5W with external power.
Sounds like I need that extra signal strength. I really should shoot for
a 4x4 signal to be kind to the folks at the other end.
Second is that I probably need to get a different mic going for some
additional punch. If I'm giving up 3 to 6 dB by not having any speech
compression, that should be an easy thing to fix. The Astatic microphone
is in the bag, but I'm not quite sure of the pin-out. I should just hook
something up and try it.
++++++++++++
Sheesh. I called CW on 10, 20 and 40 meters to no avail. Came back to one guy, but somebody else beat me to it.
Copy parts of multiple different QRS QSOs.
Very frustrating. Oh well. Patience, patience, patience...
I assembled the PAC-12 and laid it out in about 5 minutes. The longest
part was putting out the radials.
I then dialed in the multi-band coil for 40m using an MFJ-296 antenna
analyzer. I was pretty much able to get the SWR down to 1.0 or 1.1 on
the coil's "sweet spot" and was pretty much able to keep the SWR down
below 2.0 across the band.
The PAC-12 was attached to a Yaesu FT-817 running on its internal
battery pack and with the stock microphone. It was on "high" power. A
whopping 2.5 watts. The battery wasn't fully charged beforehand but it
should have been between 2/3 and 1/2 full when I started.
I tested the antenna by checking into the noon time net on 7.2685 MHz.
The network control station was coming in 5xS8. Some of the other
stations we S9+. A San Francisco station was about S2.
The outbound signal sure wasn't breaking any pile-ups but they were
eventually able to get my call. I'm guessing I was about 3x3. The net
control then tried to get me in contact with Craig, AE6RR. He was mobile
someplace in the Mountain View/Sunnyvale area. I heard Craig 5xS8. Craig
was unable to hear me. I'm betting NVIS was working but the signal was
too weak for local groundwave.
My impression is that the PAC-12 was doing better than the inverted-L
end-fed 1/2 wave strung in the trees that I normally use. Of course it
was MUCH better than the (snork) "Miracle" whip. (The miracle is that I
suspended disbelief to shell out $90 for it.) I still think that the
NVIS folded dipole is the "best" of the antennas we've tried.
I then tuned the PAC-12 up on 20m. It was about 1.5 at the "sweet spot"
and 2.0 at one end and about 2.2 at the other. Since the radio's battery
had petered out I just tuned it using the analyzer. We'll need to leave
the operating to another day.
The PAC-12 came apart about as fast as it went up. The longest part was
coiling the radials.
I also quickly tested the Palm Paddles, but didn't expect anybody to
answer my short CQ at 2.5W on 40m. They worked, that's all I was
expecting to find out.
My biggest lesson learned is that the FT-817 internal battery pack
really isn't the way to go. It doesn't hold up very long and limits the
output to 2.5W more or less. The radio goes to 5W with external power.
Sounds like I need that extra signal strength. I really should shoot for
a 4x4 signal to be kind to the folks at the other end.
Second is that I probably need to get a different mic going for some
additional punch. If I'm giving up 3 to 6 dB by not having any speech
compression, that should be an easy thing to fix. The Astatic microphone
is in the bag, but I'm not quite sure of the pin-out. I should just hook
something up and try it.
++++++++++++
Sheesh. I called CW on 10, 20 and 40 meters to no avail. Came back to one guy, but somebody else beat me to it.
Copy parts of multiple different QRS QSOs.
Very frustrating. Oh well. Patience, patience, patience...
