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

[Robert G Strickland]

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

On 1/1/2014 20:45, Robert G Strickland wrote:
> Happy New Year to all.
>
> I just got new ReSound hearing aids w/ a blue tooth amp pickup. I
> connected the blue tooth transmitter to the front panel PHONES and got
> plenty of sound but very distorted at levels necessary for operating. I
> then connected it to the LINE OUT in the back of the K3 and switched
> that output level from fixed to PHONES. The audio level for signals is
> almost too low to hear at any level of AF/RF gain, but the beep level
> for radio control is very loud.
>
> How do I get the signal output from the LINE OUT jack up to a useable
> level? Any thoughts as to why the audio from the front panel PHONES is
> so distorted? Is this a radio issue or something to do with the blue
> tooth transmitter and the hearing aids? Thanks for any and all comments.
>
> ...robert

-- 
Robert G Strickland, PhD ABPH - KE2WY
rcrgs at verizon.net.usa
Syracuse, New York, USA