[Elecraft] K3 audio line out level with blue tooth hearing aid amp

[Robert G Strickland]

Happy New Year, Don...

Using audio out from the rear speaker jack is the same as the front 
headphone jack: low audio which becomes distorted as the gain from 
either the radio or the BT transmitter is increased. I'm thinking that 
this might be a limitation in the hearing aids. I haven't checked with 
the hearing aid people about increasing the gain of the hearing aids in 
the BT mode. That's worth a try. I'll report back.

...robert

On 1/3/2014 16:55, Don Wilhelm wrote:
> Robert,
>
> What happens if you plug the Bluetooth transmitter into the speaker jack
> on the rear panel?  It is worth a try.
>
> 73,
> Don W3FPR
>
> On 1/3/2014 10:42 AM, Robert G Strickland wrote:
>> Thanks for the comments.
>>
>> Using the LINE OUT at a fixed level - whatever that might be - does
>> not allow volume control from the front panel AF/RF knobs. With this
>> setup the only volume control is on the blue tooth transmitter which
>> does not allow fine and immediate control as the operating environment
>> changes.
>>
>> With LINE OUT set to PHONES, the output level is controlled from the
>> front panel which is desirable. However, as stated in my original
>> post, there is no AF/RF setting that delivers enough <signal> volume,
>> regardless of the volume setting on the blue tooth transmitter.
>> However, while the signal level is way down, the radio control beeps
>> are at their normal volume suggesting that some adjustment/switch is
>> incorrect. What might this adjustment/switch be?
>>
>> The other issue is that sound out of the front panel audio jack, while
>> loud and controllable, is very distorted as heard via the blue tooth
>> transmitter. This may be because of an impedance mismatch; I don't
>> know right off what the input impedance of the blue tooth unit is.
>> Another reason may be a very limited dynamic range in the blue tooth
>> unit.
>>
>> The blue tooth transmitter does work as advertised when used as
>> intended: enhancing speech levels in a natural environment. This agan
>> suggests that impedance matching and/or dynamic range may be the
>> issue(s), at least when using the K3's front panel audio jack.
>>
>> ...robert
>>
>
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-- 
Robert G Strickland, PhD ABPH - KE2WY
rcrgs at verizon.net.usa
Syracuse, New York, USA