Not my weekend!

[tarbat]

Hi CoastGuardJon, glad you were able to make the "right" decision.  Looking forward to the coverage from Cornwall on the network.

Have you ever thought of using ShipPlotter, you're probably in a good location for shipping as well.

[AirNav Development]

Or better wait for AirNav ShipTrax, you will be amazed with what it does. Check www.airnavsystems.com/shiptrax

[pcochrane12]

hi dc
dont no if you still moitor this thread but have just had mye new amp fail again only a few weeks old same as last ime checked all connection for water ingress etc  found none have cotacted kuhne for pricing of there kit this time suspect static dont know how as fully earthed and bonded but hey thats my luck again

[Deadcalm]

I now have the new Kuhne preamp up and running - seems OK at the moment.
The failed one was from Wimo.  I sent it back last week for them to look at and repair if necessary (hopefully under warranty). They promised to let me know when it arrived, but I've heard nothing yet...

DC

[tarbat]

I just wonder whether the failure of Wimo pre-amps are anything to do with the fact that they don't supply a 12 power adaptor.  Maybe people are using 12v supplies that aren't suitable for the Wimo pre-amp?

It's one thing I was concerned about when I received my Wimo pre-amp.  No 12v supply, and all instructions in German.  I just hope the 12v adaptor I'm using is suitable.

[Deadcalm]

Kuhne didn't supply a power adaptor, either.  I suppose if you are aware of your PSU output specs, and they fall within the requirements of any preamp, then you should be OK.
I'm using the same PSU as I did for the Wimo, and the Wimo Bias Tee as well...

DC

[tarbat]

Well, I had two 12v adaptors available.  I checked the first, and despite being labelled as 12v, it was outputing 17v !!!   The second one output 12v, so that's the one I'm using.

I just wonder if I had used the first adaptor whether that may have then caused a failure.

The Wimo instructions only specify 12v at 100mA.  That's assuming Spannungsversorgung means voltage, and Stromaufnahme means current.

[Deadcalm]

The Kuhne Bias T (which I'm not using at the moment due to lack of N connectors) accepts a voltage range up to +15v DC, max. 1 amp.

DC

[flightchecker]

The Wimo instructions only specify 12v at 100mA.  That's assuming Spannungsversorgung means voltage, and Stromaufnahme means current.

Right tarbat
and don't care too much about the bias supplies. The 17VDC you've been measuring is the "idle voltage" (no load connected to the supplies output), that will settle at about 12VDC "nominal voltage", as soon as the amplifier  draws current (load connected) via the "Tee". The operating voltage though may not be 12VDC  exactly, but the amplifier can "live with it", if it remains within certain limits. (you might take another voltage measurement with the amplifier then connected) No need to use a "stabilized" power supply, which of course will deliver its rated voltage within a small margin. (even if there is no load connected to it)

Regards

Karl

[CoastGuardJon]

Right tarbat
and don't care too much about the bias supplies. The 17VDC you've measured is the "idling voltage" (no load connected to the supplies output), and it will settle at about 12VDC as soon as the amplifier  draws current (load connected) via the "Tee". The operating voltage though may not be 12VDC  exactly, but the amplifuer can live with that if it remains within certain limits. No need to use a "stabilized" power supply, which of course will deliver its rated voltage within a small margin. (even if there is no load connected to it)

Regards

Karl

Spot on Karl, the PSU needs to be able to supply a minimum of 100mA at 12V to work satisfactorily, but some of the PSUs around (eg those provided with re-chargeable handlamps) are not of the best quality and could well do with some modification before being used with this sort of application.