Hi,
Tell me how long you want the coax cable to be and I will make one up for
you guaranteed......and GRATIS, It will be good grade commercial US
made
coax, either 50 or 75 ohms, your choice, and by return mail.
I have an Omni VI+ and a Titan 425 and no problems here.
Note: Those RCA plugs and jacks are not always the best; specially the jack
contacts can become spread and not make good and reliable contact. RCA
plugs were designed for AUDIO, but Collins was the first to use them for low
level RF and Heath followed.............
-----Original Message-----
From: tentec-bounces@contesting.com [mailto:tentec-bounces@contesting.com]On
Behalf Of Ken Brown
Sent: Monday, September 22, 2003 5:41 PM
To: tentec@contesting.com
Subject: [TenTec] Interesting problem and solution
Hi All,
I have an Omni VI and a Titan. I recently changed the key out to tx
enable cable to what I thought was a better cable, even though it was
working fine. The origninal cable, that worked, was just a plain ten
foot long skinny stereo audio phono plug to phono plug cable ( using
only half of the cable ) and the "better" cable is a six foot Radio
Shack "Gold Series" Audio/Video cable, which appears to be made from 75
ohm coax.
With the "better" cable on 160 meters the transmitter would lock up
whenever the amplifier was putting out more than 500 watts. The watt
meter would indicate power output, and the side tone was gone, unless I
continued to intentionally key the transmitter. Reducing drive from the
Omni, or detuning the amplifier to reduce output to below about 500
watts, would unlock the system. Same thing either to a good dummy load
or to an antenna.
Putting back the cheapo, skinny, longer cable made the problem go away.
At one point I tried a couple of turns of the "better" cable through a
split ferrite core. That did not fix it.
I'm sticking with the cable that works for now. I am interested in
opinions about what is wrong with the "better" cable. Lower capacitance?
Would some additional bypass capacitors on the tx enable in the Omni
make it work with either cable? I have the amplifer and radio grounds
connected with RG-8 outer sheild braid, and am using 1/4 inch Andrew
Superflex Heliax between the Omni and the Titan. It did the same thing
with RG-58. I just used the overkill heliax cable just because it was handy.
Thanks,
Ken N6KB
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
_______________________________________________
TenTec mailing list
TenTec@contesting.com
http://lists.contesting.com/mailman/listinfo/tentec
|