[CQ-Contest] Wireless HS Eval. (long)

[MarchandJohn]

Hi All,

DISCLAIMER: I have no ties with Radio Shack, I'm just sharing some info
on the operation and potential applications of a new toy.
		[I'll try to keep it short, but no guarantees]

Well, I zoomed up to the ole R-S store last night and picked up a pair of
900 mhz wireless headsets (ON SALE). When I got them home, I was pleasently suprised at the features the unit had.

Here's the preliminary (3-4 hour) usage report (and opinions/ideas).

1. Specs as I remember: (forgot the manual at home) 
	       *Freq: 912-914mhz WBFM (tunable, chkd it with my scanner)

IDEA #1: No schematics came with the unit, but I bet these thingys could be
         narrow-banded pretty easily (for multi-station use).
         Oh man, the temptation to void the warranty and open this thing up!!
	  I THINK I'M HAVING A TWEAKER ATTACK!
	       *Power: Control Unit- 8VDC, AC adapter included.
		              Headsets- batt. powered, (nicad batts included/installed).
--You can charge the headsets from the control unit "charge" jack with the
headset charging cable (included). --
	R-S claims min 6 hours use of the headsets on a charge. (This may vary
 with how hard you drive the headsets with its own level Ctrl.)

IDEA#2. How about a powerpack w/belt clip and small cable up to the charge
	       jack on the headset, for extended use during a contest? This could
	       also power the boom-mic xmtr for phone operation.

2. Controls/plugs:  Control Unit
	    *Level control - "volume" level to the headsets.
     *Tuning control - Freq. adj to the headsets. 
		      This allows you to tune the control unit to the headsets when
        the headsets are across the room - the headsets have indicator
	       leds which light up when on freq. (nice.)
     *Left/Right channel (RCA jack) inputs. 5' stereo cable included,
        along	with a 2' Y-mating connector with 1/8 and 1/4" adapter
        stereo plugs.

IDEA #3: The L-R channel inputs may be useful for running 2 radios and
         running the audio from each radio to each channel of the headset.
         You would have to control the level to each channel with the AF
         gain on the radio itself, since there is only one common level
         control on the headset. But that could also be modified.
	    *Power - 8 vdc from (included) wall adapter for running the control
	        unit and charging the headsets when not in use.

3. Controls/plugs:  Headset unit
	    *Level control - "volume" control.
	    *Tuning control - fine tuning to stay on freq while you're walking
         around the area.
	    *On/Off switch - No explaination needed (I hope).
	    *Charge jack - Hang the headsets on the control unit, plug 'em in
                    and charge 'em between uses.

3. Setup and operation:  Initial setup for test on the entertainment center,
    took all of about 2 minutes. I used the 2 chan. audio cable/Y-cable 
    w/ 1/4" phono plug adapter and plugged the control unit into the JVC
    system. BOY- Dolby Surround is a hoot with Top Gun in the tape deck...
    The only thing missing is a G-Suit!! Setting up the tuning and level
    controls on both the control unit and headset is very simple. Adj for
    your comfort level.
          **I'd give the SETUP/LEVEL ADJ. a "Piece-O'-Cake" rating**
    
    Setting the unit up on the FT-990/homebrew audio switchbox was just as
    easy. I had to "fudge" the 1/4" jack in the switcher for mono operation.
    With levels/freq. set, the listening was very good on all modes. 
    The unit has the typical stereo response bandwidth, but that can be
    tailored to your individual taste according to modes of operation.
    I used the unit on SSB/CW/RTTY/AMTOR/SW BCST and didn't notice any bad
    habits.
    I found no problems when transmitting either. Although I only run 100w
    on HF (tried all modes) and 50w on VHF PKT, I didnt hear anything
    unusual.

Finaliy    --AT LAST--
    OVERALL, with only about 3-4 hours usage, I'd give it a 7-8 rating...
    We can slide that rating either way as time goes on... 
IDEA #3. How about a homebrew boom mike setup with a low power tunable
    "bugging" type FM xmtr, to maybe a Walkman type FM rcvr into the Mic.
    connector of your txcvr for wireless contest/general phone use??

    OH BTW, the headsets are quite comfortable to wear for long periods.

    Thats it for now, more to follow in the near future. Sorry for the
    wind-baggyness.

John K1RC   
35 mi NW of Boston



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