[hpsdr] Fwd: Hermes Ethernet

[Chris Smith]

My 3 pennyworth:

My experience of PoE is that there is a large voltage loss down standard Cat.5 cable under even moderate load. If you're considering lengthy cable runs the drop could be significant.

I gained this experience because the village that I live in has NO land-line or cable broadband. The community got together and set up a very flakey Wi-Fi (802.11a) mesh network. ALL the nodes were PoE supplied which turned into a nightmare.

Luckily we have been rescued by a commercial outfit using 5GHz kit which is still PoE supplied but seems to work well. End of aside.

Cheers

Chris G4NUX

On 5 Aug 2010, at 09:55, Henry Vredegoor wrote:

> ***** High Performance Software Defined Radio Discussion List *****
> 
> Hi Jeremy, All,
> 
> That's for 802.3at  Type 1:   12.95 Watts
> 
> For 802.3at  Type 2 it seems to be 25.50 Watts.
> 
> But I think in that case you have to spend more attention to the cabling quality and such.
> 
> 73's,
> 
> Henry.
> 
> 
> On 8/5/2010 10:44 AM, Jeremy McDermond wrote:
>> On Aug 5, 2010, at 1:33 AM, Henry Vredegoor wrote:
>> 
>>   
>> 
>>> ***** High Performance Software Defined Radio Discussion List *****
>>> 
>>> Hi Jeremy, All,
>>> 
>>> That would be a pitty!
>>> 
>>> Like Achim already said, a device only with RF-in and Ethernet-out would be very nice remote SDR indeed!
>>>     
>>> 
>> Admittedly, it would be really cool.  But if Achim's right and the spec is only 13W, I wouldn't imagine that's enough to power the transmitter in Hermes.  Apollo alone is a 10-15W out PA.  I think you might be able to get away with it in receive-only mode though.
>> 
>>   
>> 
>>> 73's,
>>> 
>>> Henry.
>>> 
>>> 
>>> On 8/5/2010 10:19 AM, Jeremy McDermond wrote:
>>>     
>>> 
>>>> On Aug 5, 2010, at 1:16 AM, Henry Vredegoor wrote:
>>>> 
>>>>   
>>>>       
>>>> 
>>>>> ***** High Performance Software Defined Radio Discussion List *****
>>>>> 
>>>>> Hi Phil,
>>>>> 
>>>>> http://en.wikipedia.org/wiki/Power_over_Ethernet
>>>>> 
>>>>> 73's
>>>>>     
>>>>>         
>>>>> 
>>>> I checked out the datasheet really quick, and it doesn't look like the Micrel chip supports the 802.3af standard.
>>>> 
>>>> 
>>>> 
>>>> --
>>>> Jeremy McDermond (NH6Z)
>>>> Xenotropic Systems
>>>> 
>>>> mcdermj at xenotropic.com
>>>> 
>>>> 
>>>> 
>>>> 
>>>>   
>>>>       
>>>> 
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>>>     
>>> 
>> --
>> Jeremy McDermond (NH6Z)
>> Xenotropic Systems
>> 
>> mcdermj at xenotropic.com
>> 
>> 
>> 
>> 
>>   
>> 
> 
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