[Premium-Rx] Rockwell HF-2050

[Charles P. Steinmetz]

Terry wrote:

>I just acquired a beautiful Rockwell Collins  HF-2050 (serial #E4-is 
>this right?)

To my knowledge, HF-2050 serial numbers are all in the form yy-xxxx, 
where "yy" is the last two digits of the year of production, such as 
86, and "xxxx" is a four-digit serial number in that year's production.

>what do I have to do to get my headphones to work and cut out the speaker?

The 2050 does not have internal switching on the headphone jack.  You 
need to do that externally.

>Also not sure if I have ISB.

I was told by an engineer who worked on the project that there are no 
2050s with ISB, because the contract was cancelled before any ISB 
units were produced.  I have also heard claims from owners who 
believe their radios have ISB, but so far nobody has been able to 
show me one that has the ISB circuitry.  (I have, however, seen units 
that had been kludged by owners or former owners to supply Channel A 
audio to both the Channel A and Channel B audio amplifiers in ISB 
mode.)  So, I do not know for certain if there are any 2050s in 
captivity with ISB, but I'm inclined to believe the engineer I spoke with.

Best regards,

Charles