Heil ProSet Headset as offered by Elecraft

[Elecraft mailing list]

Are the earphone drivers in the Heil Proset magnetically shielded?  The drivers in my Yamaha CM-500 are not and they cause problems with the telecoils (magnetic pickups) in my Kirkland Signature 7.0 hearing aids.  When running more than 100 watts on 80 or 40 the RF causes the hearing aids to switch modes randomly when the telecoils are activated by a nearby magnetic field.

None of my other headphones (Bose & Koss) cause this problem when used with the hearing aids, K3S and KPA500.  I could not find this information on either the Heil or Elecraft site.

Michael Blake
[hidden email] <mailto:[hidden email]>






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[Jim Brown-10]

Hi Michael,

Are you sure it's the headphones?  What sort of antenna are you using? 
The current in an antenna creates a magnetic field that can be quite
strong in the near field. When I lived in Chicago, my best antenna for
80 and 160 was a long wire that ended in the shack, and it had a current
maxima at the feedpoint (the shack).  The field shut down the RS232 port
in my computer sending CW to my K2 using the standard K2 cable with as
little as 12 watts! That cable used parallel wires. I fixed the problem
by replacing it with CAT5, using one pair for each of the RS232
signalling ports. Twisted pairs STRONGLY resist magnetic coupling. Once
I did that, I could crank my Titan power amp to near legal limit power.

I'm not suggesting that twisted pair is a solution, but I am suggesting
that, depending on your antenna and its proximity to your aids, that
field could be getting directly into their pickup from your antenna!

73, Jim K9YC

On 11/2/2018 1:59 PM, Michael Blake via Elecraft wrote:
> When running more than 100 watts on 80 or 40 the RF causes the hearing aids to switch modes randomly when the telecoils are activated by a nearby magnetic field.


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[Elecraft mailing list]

Jim, everythingis okay with the hearing aids in my ears and I use an SP3 speaker, Sony earbuds, Apple earbuds, KOSS PRO headphones, Bose QC25 headsets, all without any issue.  As soon as I put on the CM-500s the aids switch to magnetic input and work well until the RF is present.

The question was about the shielding in the Heil headset and not how to mitigate the RF. The levels are certainly high. I have learned that the Heil speaker elements are not shielded so I will not try them.


Michael Blake
[hidden email]

> On Nov 2, 2018, at 20:39, Jim Brown <[hidden email]> wrote:
>
> Hi Michael,
>
> Are you sure it's the headphones?  What sort of antenna are you using?  The current in an antenna creates a magnetic field that can be quite strong in the near field. When I lived in Chicago, my best antenna for 80 and 160 was a long wire that ended in the shack, and it had a current maxima at the feedpoint (the shack).  The field shut down the RS232 port in my computer sending CW to my K2 using the standard K2 cable with as little as 12 watts! That cable used parallel wires. I fixed the problem by replacing it with CAT5, using one pair for each of the RS232 signalling ports. Twisted pairs STRONGLY resist magnetic coupling. Once I did that, I could crank my Titan power amp to near legal limit power.
>
> I'm not suggesting that twisted pair is a solution, but I am suggesting that, depending on your antenna and its proximity to your aids, that field could be getting directly into their pickup from your antenna!
>
> 73, Jim K9YC
>
>> On 11/2/2018 1:59 PM, Michael Blake via Elecraft wrote:
>> When running more than 100 watts on 80 or 40 the RF causes the hearing aids to switch modes randomly when the telecoils are activated by a nearby magnetic field.
>
>
> ______________________________________________________________
> 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]

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