W2 wattmeter maximum Cat5 cable length

[wc1m]

The W2 wattmeter comes with a 5-foot Cat5 cable to connect the coupler to the display unit. I need to use a longer cable, maybe 10-15 feet. I’ve searched the reflector archives and web for any information about the max Cat5 cable length but haven’t found any.

Does anyone know? Does the calibration routine in the W2 Utility compensate for different cable lengths?

73, Dick WC1M

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

[Jeff Schmidt]

the standard cable is not Cat5, it's just a ribbon cable with RJ45's (I
think?) at each end.
Cat5 should work, though, and I'd be surprised if anything less than ~50ft+
would be an issue.

--
Jeff KC9WSJ <[hidden email]>

On Mon, 2018-07-09 at 23:51 -0400, Dick Green wrote:
> The W2 wattmeter comes with a 5-foot Cat5 cable to connect the coupler to
> the display unit. I need to use a longer cable, maybe 10-15 feet. I’ve
> searched the reflector archives and web for any information about the max
> Cat5 cable length but haven’t found any.
>
> Does anyone know? Does the calibration routine in the W2 Utility
> compensate for different cable lengths?
>
> 73, Dick WC1M
______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

[wc1m]

Thanks. First real info I've gotten. I said Cat5 because the documentation mentions it and I believe it says you can use a standard Ethernet cable.

I haven't taken a close look at the coupler circuitry. If it's like most remote couplers I've seen, a too-long cable can cause a drop in the DC voltages that carry the forward and reflected power signals. If the coupler does a conversion to digital, then the cable length wouldn't be an issue. But that sounds pretty fancy!

73, Dick WC1M

-----Original Message-----
From: Jeff KC9WSJ <[hidden email]>
Sent: Tuesday, July 10, 2018 12:47 PM
To: [hidden email]
Subject: Re: [Elecraft] W2 wattmeter maximum Cat5 cable length

the standard cable is not Cat5, it's just a ribbon cable with RJ45's (I
think?) at each end.
Cat5 should work, though, and I'd be surprised if anything less than ~50ft+ would be an issue.

--
Jeff KC9WSJ <[hidden email]>

On Mon, 2018-07-09 at 23:51 -0400, Dick Green wrote:

> The W2 wattmeter comes with a 5-foot Cat5 cable to connect the coupler
> to the display unit. I need to use a longer cable, maybe 10-15 feet.
> I’ve searched the reflector archives and web for any information about
> the max
> Cat5 cable length but haven’t found any.
>
> Does anyone know? Does the calibration routine in the W2 Utility
> compensate for different cable lengths?
>
> 73, Dick WC1M

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]

[Elecraft mailing list]

The cable is indeed not cat-5, but rather 8 individual wires that carry power and ground one way (to the box) and analog sensor signals back. The twist action in CAT-5 does not help here at all.
The things to watch for are signal loss due to resistance (shouldn’t be too bad, depending on the wire and length), and RF pickup. The latter can lead to bad and erratic readings.
The best advice is to keep the cable as short as possible.

73,
Jack, W6FB

> On Jul 10, 2018, at 12:06 PM, Dick Green WC1M <[hidden email]> wrote:
>
> Thanks. First real info I've gotten. I said Cat5 because the documentation mentions it and I believe it says you can use a standard Ethernet cable.
>
> I haven't taken a close look at the coupler circuitry. If it's like most remote couplers I've seen, a too-long cable can cause a drop in the DC voltages that carry the forward and reflected power signals. If the coupler does a conversion to digital, then the cable length wouldn't be an issue. But that sounds pretty fancy!
>
> 73, Dick WC1M
>
> -----Original Message-----
> From: Jeff KC9WSJ <[hidden email]>
> Sent: Tuesday, July 10, 2018 12:47 PM
> To: [hidden email]
> Subject: Re: [Elecraft] W2 wattmeter maximum Cat5 cable length
>
> the standard cable is not Cat5, it's just a ribbon cable with RJ45's (I
> think?) at each end.
> Cat5 should work, though, and I'd be surprised if anything less than ~50ft+ would be an issue.
>
> --
> Jeff KC9WSJ <[hidden email]>
>
> On Mon, 2018-07-09 at 23:51 -0400, Dick Green wrote:
>> The W2 wattmeter comes with a 5-foot Cat5 cable to connect the coupler
>> to the display unit. I need to use a longer cable, maybe 10-15 feet.
>> I’ve searched the reflector archives and web for any information about
>> the max
>> Cat5 cable length but haven’t found any.
>>
>> Does anyone know? Does the calibration routine in the W2 Utility
>> compensate for different cable lengths?
>>
>> 73, Dick WC1M
>
>
> ______________________________________________________________
> Elecraft mailing list
> Home: http://mailman.qth.net/mailman/listinfo/elecraft
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:[hidden email]
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
> Message delivered to [hidden email]

______________________________________________________________
Elecraft mailing list
Home: http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/mmfaq.htm
Post: mailto:[hidden email]

This list hosted by: http://www.qsl.net
Please help support this email list: http://www.qsl.net/donate.html
Message delivered to [hidden email]