[sarcmembers] Re: SARC Tower and Dish move...
- From: "John Maetta" <j.maetta@xxxxxxxxxxx>
- To: <sarcmembers@xxxxxxxxxxxxx>
- Date: Sun, 10 May 2009 09:10:13 -0700
I agree with John P.'s assessment and propose the following:
In an effort to get the SARC on the 6 meter band, I will donate a 5 element
50MHz yagi to install on the portable roof tower. Along with that, I will
donate a Cushcraft 13B2 144MHz yagi for the portable roof tower.
We can troubleshoot the log periodic at our leisure, and reinstall it if
decided.
I will have a day or so over the Memorial Day weekend and will try to get the
two antennas (50Mhz and 144MHz) mounted and tested. Hopefully, I can have it
ready and use the station on 50MHz during the June VHF contest. If someone has
a 220Mhz yagi, now would be a good time to get it mounted too.
Does the SARC have enough 9913 or equivalent to make another run or two up to
the portable tower? Is the radio room penetration have enough room for another
coax or two?
In addition, we noted that SARC's the horizontal 144MHz, on coax 'B' exhibited
2.5:1 SWR at 144.200MHz. Something else to troubleshoot in the future.
73
John
----- Original Message -----
From: jportune@xxxxxxx
To: sarcmembers@xxxxxxxxxxxxx
Sent: Sunday, May 10, 2009 8:30 AM
Subject: [sarcmembers] Re: SARC Tower and Dish move...
My phone is 805-406-6176. But on a conventional SWR bridge you should not be
getting high SWR. So if you are, you do have a problem which is not due to the
basic design of the antenna. Other than that I really do not have any other
suggestion. Call if you wish, though.
John W6NBC
----- Original Message -----
From: george bernard
To: sarcmembers@xxxxxxxxxxxxx
Sent: Sunday, May 10, 2009 8:26 AM
Subject: [sarcmembers] Re: SARC Tower and Dish move...
john, i think you are correct. can you call me on home fone?
805-688-6324 and we can discuss what to do about this $1500 antenna? how do we
use it? do we just have to tolerate the high swr? george
santa barbara, ca web page is
www.balanceindustries.com for my company cell 818-370-9407
----------------------------------------------------------------------------
From: jportune@xxxxxxx
Sent: Sunday, May 10, 2009 8:22 AM
To: sarcmembers@xxxxxxxxxxxxx
Subject: [sarcmembers] Re: SARC Tower and Dish move...
Rember basic radio theory. A log-periodic is basically a NON-resonant
antenna. So "some" instruments may not see it correctly. But on a basic SWR
bridge is should show low SWR on any requency within its range.
----- Original Message -----
From: george bernard
To: sarcmembers@xxxxxxxxxxxxx
Sent: Sunday, May 10, 2009 8:09 AM
Subject: [sarcmembers] Re: SARC Tower and Dish move...
john, do you think that a log periodic antenna might not resonate on
any ham bands? it is covering 50-1300 mcs so maybe
it doesnt dip like we expected it to on 144.2? perhaps i should just
call ted henry at hrc and purchase a 15 element yage for that tower/rotator and
call it quits with the log periodic? it worked fine for me in goleta on six
and two meters and also on 432.12 ssb. thank you for donating the use of
your 70 amps for this rig. we need to tell all members not to run power up
past 300 watts as you recommend and also
how do you want to proceed on the landwehr preamp which is in the
workshop area? btw i got the ultrasonic bird repeller installed in my
airplane hangar at smx airport yesterday. it is made by Bird-X.com company
of chicago, cost was only
$249. regards, george bernard w6nre
PS: the photo of the explorer sheriff scouts who are using my donated
"black box uhf radios" on 460.275 and .325 were useful by visiting police
officers from other jurisdistricts working the fire. sheriff brown allowed us
to program channels 1-7 to the same freqs as the regular motorolas which his
peole carry. i bought 24 of them and a computer to program the freqs. channels
8-16 are gmrs channels for the kids to talk with each other. these are
only $150 each so if they fail we delete the serial number and trash the radio.
if one gets lost we dont worry about it.
santa barbara, ca web page is
www.balanceindustries.com for my company cell 818-370-9407
--------------------------------------------------------------------------
From: John Maetta
Sent: Sunday, May 10, 2009 7:22 AM
To: sarcmembers@xxxxxxxxxxxxx
Subject: [sarcmembers] SARC Tower and Dish move...
All,
Yesterday, with the help of Bob, W6RFH, we were able to reposition the
EME dish and portable tower. The new locations allow much shorter control and
hardline runs to the operating positions. My special thanks to Bob, for his
expertise in delicately moving of the fully loaded EME tower.
www.n6vmo.com/arpics/SARCTowerandDishMoveMay92009/index.html
I have loaned SARC the use of my Astron RS-70 powersupply to power the TE
Systems 144MHz amplifier. It is modified to power and provide cooling air to
the amplifier.
Later, W6NRE arrived and we discovered during testing, that the log
periodic antenna exhibited high SWR on 144.200MHz We also noted that the
antenna was not resonate on any amateur band or frequencies in the VHF range.
The log periodic antenna was taken down for further troubleshooting and the
tower is currently laying flat on the SARC roof.
The 1.29GHz amplifer has new cooling water and tested to 200 watts
output, it should be ready for 1.2Ghz EME operation by June 6th. Hopefully,
after the monthly meeting, it can be successfully demonstrated by providing our
first 1296MHz EME contact.
This past week, I noted an ad on QTH.com for a almost new 12' parabolic
TVRO dish. The dish is for sale and located in Solvang. I emailed the seller
and asked if he had not sold it, would he be interested in donating it to the
club. He happily agreed. If it becomes available, and meets with the board's
approval, along with focal and mounting requirements, I will meet with him to
transport it to the club, swap it out with the current 10' dish. The 10' dish
will then leave for the dump, unless a club member wants it.
The new dish will provide ~50% more reflective surface area than the 10'
dish. This extra surface area will add ~2.8dB of gain, effectively almost
doubling the ERP and adding ~1/2 S-Unit of received signal strength.
73
John
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