HF Radio Issue

Submitted: Sunday, Apr 30, 2006 at 17:26

ThreadID: 33381 Views:1942 Replies:5 FollowUps:13

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jdpatrol

We enjoyed a great trip up Goog’s track north of Ceduna last week and then down through Gawler Ranges.

I was reporting in to VKS (Adelaide) from Mt Finke and half way through the call they suddenly could not hear me. In the days after that I was able to Beacon and Selcall a mate in Adelaide, hear sched’s etc, but no has since been able to hear me including VKS Alice Springs who we also communicated with earlier in our trip. I don’t know why. Can anyone suggest anything that might be wrong?

Our HF is a Codan 9323 / antenna is a 9350 autotune (Series A).

Thanks in anticipation.
JD

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Reply By: Marc - Sunday, Apr 30, 2006 at 17:33

Sunday, Apr 30, 2006 at 17:33

are you sure the mic is working? and not a lose plug fitting?
Have you checked all the earths and connection points as they may have vibrated with the trip and you need excellent connections to transmit

AnswerID: 169857

Follow Up By: jdpatrol - Sunday, Apr 30, 2006 at 17:59

Sunday, Apr 30, 2006 at 17:59

Marc
I unwound it and blew it out and reconnected. Beacon/selcall sent with mic so I think it's working.
thanks
JD

FollowupID: 425213

Follow Up By: Mad Dog (Australia) - Sunday, Apr 30, 2006 at 18:14

Sunday, Apr 30, 2006 at 18:14

did you receive an answer ?

FollowupID: 425222

Follow Up By: jdpatrol - Sunday, Apr 30, 2006 at 18:42

Sunday, Apr 30, 2006 at 18:42

Mad Dog
I heard the beacon tune come back and my mate in Adelaide responded to the selcall. But he just couldn't hear us.
JD

FollowupID: 425228

Follow Up By: Mad Dog (Australia) - Sunday, Apr 30, 2006 at 18:49

Sunday, Apr 30, 2006 at 18:49

You have an mic problem, could be as simple as a broken wire

FollowupID: 425233

Follow Up By: jdpatrol - Sunday, Apr 30, 2006 at 19:07

Sunday, Apr 30, 2006 at 19:07

thanks again Mad Dog
Looking at Wayne's experience and your advice, seems no doubt it's a mic problem.
JD

FollowupID: 425239

Follow Up By: angler - Sunday, Apr 30, 2006 at 21:47

Sunday, Apr 30, 2006 at 21:47

Having worked in the area of mobile radios for many years I found the most common problem with all vehicle radios was microphone cable failure.
This is the result of the mike hanging up somewhere and the cable hanging down and into the radio input socket. The continuous bouncing of the hanging cable results in a wire breakage.
Also if it has happened, change the whole cable cause if one is broken the others will not be far behind.
Always drape the cable over something to stop it from bouncing around.

Pooley
www.bycompass.com

FollowupID: 425292

Reply By: Member - Mike DID - Sunday, Apr 30, 2006 at 17:36

Sunday, Apr 30, 2006 at 17:36

You need to realise that

1. an antenna needs to be precisely tuned to work on transmit - on receive it is a lot less critical.

2. conditions on HF mean that sometimes you can get through on one tenth of a watt and other times ten thousand watts won't get through over the same distance. The automatic gain control means that signal strength change over a thousand to one can sound the same.

3. You may be able to hear station 1000km away perfectly, but can hear nothing of a station 200km away.

So it could be that something has broken in your aerial and it is working but very badly - the 9350A's have a reputation for problems.

Mike

AnswerID: 169858

Follow Up By: jdpatrol - Sunday, Apr 30, 2006 at 18:02

Sunday, Apr 30, 2006 at 18:02

Mike
I have heard about the problems with series A antenna which is one thing Im worrying about. Im still hoping it might be something simpler and cheaper!!
thanks
JD

FollowupID: 425215

Follow Up By: jdpatrol - Sunday, Apr 30, 2006 at 18:08

Sunday, Apr 30, 2006 at 18:08

Forgot to say also, that I calculated (roughly) 8meg was about the right frequency for the time/distance over which we were transmitting. Kept away from power lines, weather was good, tried car engine on and off etc.
JD

FollowupID: 425217

Reply By: Pilbara Wayne - Sunday, Apr 30, 2006 at 18:12

Sunday, Apr 30, 2006 at 18:12

Hi JD

Mine did exactly the same thing two weeks ago. Had it looked at in Perth and I needed a new mike.

Cheers

Wayne

Cheers

Wayne

Member
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AnswerID: 169868

Follow Up By: jdpatrol - Sunday, Apr 30, 2006 at 18:43

Sunday, Apr 30, 2006 at 18:43

Ouch - from memory mic's cost a bit? What did it cost you Wayne? Was cord replaced also?

My Mic cord is new - I am wondering now if solder job might have failed on one of the wires.

JD

FollowupID: 425229

Follow Up By: Pilbara Wayne - Monday, May 01, 2006 at 21:27

Monday, May 01, 2006 at 21:27

New mike cost $220 plus GST. Cost me $90 for one hour to find that out too!

Check on Ebay, I've seen some on there before.

Cheers

Wayne

Member
My Profile My Position Send Message

FollowupID: 425484

Follow Up By: jdpatrol - Monday, May 01, 2006 at 21:44

Monday, May 01, 2006 at 21:44

thanks for the info Wayne

FollowupID: 425491

Reply By: Member - Jerry C (WA) - Sunday, Apr 30, 2006 at 22:02

Sunday, Apr 30, 2006 at 22:02

Hi jdpatrol,
I will suggest that you need a new microphone insert, they cost about $25 and just drop in and don't need soldering, I have replaced two in the last couple of months.

Cheers, Jerry

AnswerID: 169927

Follow Up By: jdpatrol - Tuesday, May 02, 2006 at 10:59

Tuesday, May 02, 2006 at 10:59

Jerry
What is an insert??
JD

FollowupID: 425544

Reply By: Member - Jerry C (WA) - Wednesday, May 03, 2006 at 00:49

Wednesday, May 03, 2006 at 00:49

Hi JD,
The insert is the transducer or if you like the interface to convert the audible sound to an electrical signal. Basically it is a loudspeaker working in reverse.
In this case it is approx 15mm diameter and 20mm long and has two terminals on one end which will require soldeing, I just had to open mine up to check.

Cheers, Jerry.

AnswerID: 170349