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PB

Paul Brannon

Sat, Apr 8, 2006 10:07 PM

I have replaced my two radios and now have a new problem. I keep one radio on
CH 9 and the other on CH 16. When I transmit on CH 9 the radio tuned to 16
receives the broadcast and will create feedback on the bridge. It also seems
that I have a very weak transmitting signal at times but no problem at other
times. I have replaced the Pl 259 connectors to eliminate any corrosion
problems. If I change out one of the radios to a spare that I have on board,
the problem does not present. The problem exists regardless of which radio is
tuned to 9 or 16. They are on separate antennas; one a 9db and the other 6db.
I tried two other brand new radios and they exhibited the same problem.

Any ideas?

Thanks,

Paul Brannon
MV SEASEA
1978 Gulfstar 44 MC

I have replaced my two radios and now have a new problem. I keep one radio on CH 9 and the other on CH 16. When I transmit on CH 9 the radio tuned to 16 receives the broadcast and will create feedback on the bridge. It also seems that I have a very weak transmitting signal at times but no problem at other times. I have replaced the Pl 259 connectors to eliminate any corrosion problems. If I change out one of the radios to a spare that I have on board, the problem does not present. The problem exists regardless of which radio is tuned to 9 or 16. They are on separate antennas; one a 9db and the other 6db. I tried two other brand new radios and they exhibited the same problem. Any ideas? Thanks, Paul Brannon MV SEASEA 1978 Gulfstar 44 MC

D

dd@gregsteckel.com

Sat, Apr 8, 2006 11:33 PM

The problem could be that the two antennas are too close in proximity.
Regardless of the frequency difference, there is enough wattage from the
transmitting antenna getting into the other receiver - on Navy ships the
receive and transmit antennae are usually separated AFT & FWD or Port &
STRBD (If beam is wide enough)

Greg Steckel (retired Navy ET)
M/V Different Drummer
President 35 Sundeck

www.chesapeaketrawlering.com
www.chesapeakesailor.com
www.fmyc.org

-----Original Message-----
From: trawlers-and-trawlering-bounces+dd=gregsteckel.com@lists.samurai.com
[mailto:trawlers-and-trawlering-bounces+dd=gregsteckel.com@lists.samurai.com
] On Behalf Of Paul Brannon
Sent: Saturday, April 08, 2006 6:08 PM
To: trawlers-and-trawlering@lists.samurai.com
Subject: T&T: VHF problems

I have replaced my two radios and now have a new problem. I keep one radio
on CH 9 and the other on CH 16. When I transmit on CH 9 the radio tuned to
16 receives the broadcast and will create feedback on the bridge. It also
seems that I have a very weak transmitting signal at times but no problem at
other times. I have replaced the Pl 259 connectors to eliminate any
corrosion problems. If I change out one of the radios to a spare that I
have on board, the problem does not present. The problem exists regardless
of which radio is tuned to 9 or 16. They are on separate antennas; one a
9db and the other 6db.
I tried two other brand new radios and they exhibited the same problem.

Any ideas?

Thanks,

Paul Brannon
MV SEASEA
1978 Gulfstar 44 MC

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The problem could be that the two antennas are too close in proximity. Regardless of the frequency difference, there is enough wattage from the transmitting antenna getting into the other receiver - on Navy ships the receive and transmit antennae are usually separated AFT & FWD or Port & STRBD (If beam is wide enough) Greg Steckel (retired Navy ET) M/V Different Drummer President 35 Sundeck ____________________ www.chesapeaketrawlering.com www.chesapeakesailor.com www.fmyc.org -----Original Message----- From: trawlers-and-trawlering-bounces+dd=gregsteckel.com@lists.samurai.com [mailto:trawlers-and-trawlering-bounces+dd=gregsteckel.com@lists.samurai.com ] On Behalf Of Paul Brannon Sent: Saturday, April 08, 2006 6:08 PM To: trawlers-and-trawlering@lists.samurai.com Subject: T&T: VHF problems I have replaced my two radios and now have a new problem. I keep one radio on CH 9 and the other on CH 16. When I transmit on CH 9 the radio tuned to 16 receives the broadcast and will create feedback on the bridge. It also seems that I have a very weak transmitting signal at times but no problem at other times. I have replaced the Pl 259 connectors to eliminate any corrosion problems. If I change out one of the radios to a spare that I have on board, the problem does not present. The problem exists regardless of which radio is tuned to 9 or 16. They are on separate antennas; one a 9db and the other 6db. I tried two other brand new radios and they exhibited the same problem. Any ideas? Thanks, Paul Brannon MV SEASEA 1978 Gulfstar 44 MC _______________________________________________ http://lists.samurai.com/mailman/listinfo/trawlers-and-trawlering To unsubscribe send email to trawlers-and-trawlering-request@lists.samurai.com with the word UNSUBSCRIBE and nothing else in the subject or body of the message. Trawlers & Trawlering and T&T are trademarks of Water World Productions. Unauthorized use is prohibited.

MM

Mike Maurice

Sat, Apr 8, 2006 11:35 PM

"Paul Brannon" pb@mvseasea.com
At 06:07 PM 4/8/2006 -0400, you wrote:

receives the broadcast and will create feedback on the bridge. It also seems
that I have a very weak transmitting signal at times but no problem at other
the problem does not present. The problem exists regardless of which radio is
tuned to 9 or 16. They are on separate antennas; one a 9db and the other 6db.

I would estimate that you have 2 problems.

Some transmitting problem that results in a weak output.
Radios with poor selectivity on receive, that allows channel 9 to
bleed over onto another channel, such as 16..

If #2 is correct, the only solution is radios with better
selectivity. If that is not feasible, you might get by if the
antennas can be moved further apart. Or, if you can install a blanker
to disconnect the antenna of the receiving radio whenever the other
unit is transmitting.

Poor selectivity on receive is generally associated with inexpensive
receivers. By the way this is a common problem.

Mike

Capt. Mike Maurice
Tualatin(Portland), Oregon

"Paul Brannon" <pb@mvseasea.com> At 06:07 PM 4/8/2006 -0400, you wrote: >receives the broadcast and will create feedback on the bridge. It also seems >that I have a very weak transmitting signal at times but no problem at other >the problem does not present. The problem exists regardless of which radio is >tuned to 9 or 16. They are on separate antennas; one a 9db and the other 6db. I would estimate that you have 2 problems. 1. Some transmitting problem that results in a weak output. 2. Radios with poor selectivity on receive, that allows channel 9 to bleed over onto another channel, such as 16.. If #2 is correct, the only solution is radios with better selectivity. If that is not feasible, you might get by if the antennas can be moved further apart. Or, if you can install a blanker to disconnect the antenna of the receiving radio whenever the other unit is transmitting. Poor selectivity on receive is generally associated with inexpensive receivers. By the way this is a common problem. Mike Capt. Mike Maurice Tualatin(Portland), Oregon

RR

Ron Rogers

Sun, Apr 9, 2006 1:03 AM

This is the issue on my boat and the antennas are mounted as far apart on
the flybridge as is feasible. I intend to place two 6db can antennas on the
top of my mast to gain the widest separation from the 9 and 10db whip
antennas. On the flybridge, one radio will go to a 6 db masthead and the
other to a whip. Likewise at the lower helm. My ICOM's have excellent
receivers. At present they "blank" one another out. You cannot hear a 16
transmission on 13.

Ron Rogers

----- Original Message -----
From: dd@gregsteckel.com

| The problem could be that the two antennas are too close in proximity.
| Regardless of the frequency difference, there is enough wattage from the
| transmitting antenna getting into the other receiver - on Navy ships the
| receive and transmit antennae are usually separated AFT & FWD or Port &
| STRBD (If beam is wide enough.)

This is the issue on my boat and the antennas are mounted as far apart on the flybridge as is feasible. I intend to place two 6db can antennas on the top of my mast to gain the widest separation from the 9 and 10db whip antennas. On the flybridge, one radio will go to a 6 db masthead and the other to a whip. Likewise at the lower helm. My ICOM's have excellent receivers. At present they "blank" one another out. You cannot hear a 16 transmission on 13. Ron Rogers ----- Original Message ----- From: <dd@gregsteckel.com> | The problem could be that the two antennas are too close in proximity. | Regardless of the frequency difference, there is enough wattage from the | transmitting antenna getting into the other receiver - on Navy ships the | receive and transmit antennae are usually separated AFT & FWD or Port & | STRBD (If beam is wide enough.)

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VHF problems