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

[Don Wilhelm]

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
>