[hpsdr] Fwd: Hermes Ethernet

[Henry Vredegoor]

Hi Chris, All,

That is what I meant by "spending more attention to the cabling...."
Use of (short) thicker wires and parraleled "unused wires" and contacts 
to minimise voltage drop over the cables / connections.
But I agree it probalbly will work best for RX-only or/and a low power 
transmitter setting.

73's,

Henry.


On 8/5/2010 11:16 AM, Chris Smith wrote:
> ***** High Performance Software Defined Radio Discussion List *****
>
> 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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