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TRS connectors - Heil Foster adapter

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TRS connectors - Heil Foster adapter

Chuck, KE9UW wrote =

// You cannot use Heil's adapter for the front panel Foster 8 pin connector on the K3s because they short the ring to the sleeve for some unknown reason. So in order to use the K3s front panel 8pin Foster socket, you need to make your own Foster to stereo mini phone connector adapter. Only two connections and DX Engineering has an excellent Foster plug. Ignore the reference to Heil Replacement Part, it's just the same old Foster 8 pin plug for all mics and rigs. //

The PC standard is for electret bias to be supplied to the tip and ring of a tip, ring, shield (TRS) connector with audio from the microphone entering the PC on the tip. The around 8 vdc bias is to be supplied via isolating TWO resistors, one to the tip and one to the ring.

Low budget USB soundcard adapters use ONE resistor supplying bias voltage to both the tip and ring which are thus shorted together within the adapter. My Heil ProSet 3.5 mm microphone plug has no ring, just an extended sleeve. So, essentially the Heil microphone plug has the ring and shield shorted together, and the cheap USB adapter shorts the tip and ring, so inserting a Heil microphone plug results in the tip, ring and shield all being shorted together. The microphone would get no electret bias, and the audio it can’t produce is shorted to ground, too. On the other hand, good PC soundcards use TWO resistors and the Heil ProSet works fine with them!

I believe in trust but verify. Chuck is correct, plugging a TRS aka stereo jumper cable into the 3.5 mm microphone jack on my K2/K3 Heil adapter and checking things with my Fluke DVM reveals that somewhere in the adapter the ring and shield are shorted together; maybe in the way things are wired, may be in the Foster plug.

Continuing, with the K3 MIC-SEL sent to RPL-BIAS, at the rear-panel connector relative to the shield there is 7 VDC of bias applied to the tip, and the ring seems to float. With power OFF, the resistance between tip and shield was about 4.5 megohms and between the ring and shield even higher.

Thanks Chuck, I learned something. It was a good day.

Bob R – N7WY

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Bob McGraw - K4TAX

Re: TRS connectors - Heil Foster adapter

What ever happened to the idea of making ones own mike cables? Two
connectors, plus a length of 2 conductor shielded cable and a bit of
careful soldering, specially on the Foster plug.    Just use a good
quality XLR connector such as Cannon or Neutrik. It isn't "rocket
science" and it is much less expensive than buying an expensive cable
plus and adapter and trying to figure out why it doesn't work.   All of
the drawings and information is in the manual.   And for less than $10
you will have a good quality working cable which is the exact length you
need and a project for which you'll be proud.

If you don't feel you are able to do this, then check with some of the
members in your radio club.

73

Bob, K4TAX

On 2/11/2019 6:39 PM, Robert Rennard via Elecraft wrote:

> Chuck, KE9UW wrote =
>
> // You cannot use Heil's adapter for the front panel Foster 8 pin connector on the K3s because they short the ring to the sleeve for some unknown reason. So in order to use the K3s front panel 8pin Foster socket, you need to make your own Foster to stereo mini phone connector adapter. Only two connections and DX Engineering has an excellent Foster plug. Ignore the reference to Heil Replacement Part, it's just the same old Foster 8 pin plug for all mics and rigs. //
>
> The PC standard is for electret bias to be supplied to the tip and ring of a tip, ring, shield (TRS) connector with audio from the microphone entering the PC on the tip. The around 8 vdc bias is to be supplied via isolating TWO resistors, one to the tip and one to the ring.
>
> Low budget USB soundcard adapters use ONE resistor supplying bias voltage to both the tip and ring which are thus shorted together within the adapter. My Heil ProSet 3.5 mm microphone plug has no ring, just an extended sleeve. So, essentially the Heil microphone plug has the ring and shield shorted together, and the cheap USB adapter shorts the tip and ring, so inserting a Heil microphone plug results in the tip, ring and shield all being shorted together. The microphone would get no electret bias, and the audio it can’t produce is shorted to ground, too. On the other hand, good PC soundcards use TWO resistors and the Heil ProSet works fine with them!
>
> I believe in trust but verify. Chuck is correct, plugging a TRS aka stereo jumper cable into the 3.5 mm microphone jack on my K2/K3 Heil adapter and checking things with my Fluke DVM reveals that somewhere in the adapter the ring and shield are shorted together; maybe in the way things are wired, may be in the Foster plug.
>
> Continuing, with the K3 MIC-SEL sent to RPL-BIAS, at the rear-panel connector relative to the shield there is 7 VDC of bias applied to the tip, and the ring seems to float. With power OFF, the resistance between tip and shield was about 4.5 megohms and between the ring and shield even higher.
>
> Thanks Chuck, I learned something. It was a good day.
>
> Bob R – N7WY

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ke9uw

Re: TRS connectors - Heil Foster adapter

In reply to this post by Elecraft mailing list

I investigated the Heil Foster adapter and the shorted ring-sleeve is inside the 1/8 inch phono jack. Not in the easily fixed Foster plug. So it cannot be fixed...reasonably. Why short it making the adapter unusable for the excellent and reasonably priced gamer headsets?

Chuck Hawley
[hidden email]

Amateur Radio, KE9UW
aka Jack, BMW Motorcycles

________________________________
From: [hidden email] <[hidden email]> on behalf of Robert Rennard via Elecraft <[hidden email]>
Sent: Monday, February 11, 2019 6:39 PM
To: [hidden email]
Subject: [Elecraft] TRS connectors - Heil Foster adapter

Chuck, KE9UW wrote =

// You cannot use Heil's adapter for the front panel Foster 8 pin connector on the K3s because they short the ring to the sleeve for some unknown reason. So in order to use the K3s front panel 8pin Foster socket, you need to make your own Foster to stereo mini phone connector adapter. Only two connections and DX Engineering has an excellent Foster plug. Ignore the reference to Heil Replacement Part, it's just the same old Foster 8 pin plug for all mics and rigs. //

The PC standard is for electret bias to be supplied to the tip and ring of a tip, ring, shield (TRS) connector with audio from the microphone entering the PC on the tip. The around 8 vdc bias is to be supplied via isolating TWO resistors, one to the tip and one to the ring.

Low budget USB soundcard adapters use ONE resistor supplying bias voltage to both the tip and ring which are thus shorted together within the adapter. My Heil ProSet 3.5 mm microphone plug has no ring, just an extended sleeve. So, essentially the Heil microphone plug has the ring and shield shorted together, and the cheap USB adapter shorts the tip and ring, so inserting a Heil microphone plug results in the tip, ring and shield all being shorted together. The microphone would get no electret bias, and the audio it can’t produce is shorted to ground, too. On the other hand, good PC soundcards use TWO resistors and the Heil ProSet works fine with them!

I believe in trust but verify. Chuck is correct, plugging a TRS aka stereo jumper cable into the 3.5 mm microphone jack on my K2/K3 Heil adapter and checking things with my Fluke DVM reveals that somewhere in the adapter the ring and shield are shorted together; maybe in the way things are wired, may be in the Foster plug.

Continuing, with the K3 MIC-SEL sent to RPL-BIAS, at the rear-panel connector relative to the shield there is 7 VDC of bias applied to the tip, and the ring seems to float. With power OFF, the resistance between tip and shield was about 4.5 megohms and between the ring and shield even higher.

Thanks Chuck, I learned something. It was a good day.

Bob R – N7WY

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Chuck, KE9UW

Don Wilhelm

Re: TRS connectors - Heil Foster adapter

Chuck,

The solution is easy (in my mind). Just plug the TRS plug into the
K3/K3S rear panel mic jack. That jack is a stereo type, but the ring is
not connected to anything. No adapter required.

If you want to use the front panel 8 pin Foster jack, you will have to
build you own adapter.

All microphones that are designed for computer (gaming) use have a TRS
plug - but the tip and ring are wired together. That includes the much
used CM500 headset and many others. Yes, when used with Heil adapters,
they will not work because the ring is shorted to the shell. The Heil
adapters are designed for mono plugs normally used on the Heil headsets.

73,
Don W3FPR

On 2/12/2019 9:41 AM, hawley, charles j jr wrote:
> I investigated the Heil Foster adapter and the shorted ring-sleeve is inside the 1/8 inch phono jack. Not in the easily fixed Foster plug. So it cannot be fixed...reasonably. Why short it making the adapter unusable for the excellent and reasonably priced gamer headsets?
>
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Elecraft mailing list

Re: TRS connectors - Heil Foster adapter

Don, it also seems obvious that the 1/8” TRS female, use by Heil on their adapter, with the ring shorted to the sleeve serves only one purpose. That would be to prevent using less costly, higher quality gaming headsets with their adapters.

73 - Mike - K9JRI

> On Feb 12, 2019, at 10:43 AM, Don Wilhelm <[hidden email]> wrote:
>
> Chuck,
>
> The solution is easy (in my mind). Just plug the TRS plug into the K3/K3S rear panel mic jack. That jack is a stereo type, but the ring is not connected to anything. No adapter required.
>
> If you want to use the front panel 8 pin Foster jack, you will have to build you own adapter.
>
> All microphones that are designed for computer (gaming) use have a TRS plug - but the tip and ring are wired together. That includes the much used CM500 headset and many others. Yes, when used with Heil adapters, they will not work because the ring is shorted to the shell. The Heil adapters are designed for mono plugs normally used on the Heil headsets.
>
> 73,
> Don W3FPR
>
> On 2/12/2019 9:41 AM, hawley, charles j jr wrote:
>> I investigated the Heil Foster adapter and the shorted ring-sleeve is inside the 1/8 inch phono jack. Not in the easily fixed Foster plug. So it cannot be fixed...reasonably. Why short it making the adapter unusable for the excellent and reasonably priced gamer headsets?
> ______________________________________________________________
> 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]

ke9uw

Re: TRS connectors - Heil Foster adapter

In reply to this post by Don Wilhelm

Right! I did end up buying a couple of Heil "Replacement" Foster 8 pin Plugs from DX Engineering. They, by the way, are excellent plugs. Much higher quality than the run of the mill that one finds at hamfests. And I made my own adapter.

Chuck KE9UW
[hidden email]

Sent from my iPad

> On Feb 12, 2019, at 9:43 AM, Don Wilhelm <[hidden email]> wrote:
>
> Chuck,
>
> The solution is easy (in my mind). Just plug the TRS plug into the K3/K3S rear panel mic jack. That jack is a stereo type, but the ring is not connected to anything. No adapter required.
>
> If you want to use the front panel 8 pin Foster jack, you will have to build you own adapter.
>
> All microphones that are designed for computer (gaming) use have a TRS plug - but the tip and ring are wired together. That includes the much used CM500 headset and many others. Yes, when used with Heil adapters, they will not work because the ring is shorted to the shell. The Heil adapters are designed for mono plugs normally used on the Heil headsets.
>
> 73,
> Don W3FPR
>
>> On 2/12/2019 9:41 AM, hawley, charles j jr wrote:
>> I investigated the Heil Foster adapter and the shorted ring-sleeve is inside the 1/8 inch phono jack. Not in the easily fixed Foster plug. So it cannot be fixed...reasonably. Why short it making the adapter unusable for the excellent and reasonably priced gamer headsets?

Chuck, KE9UW