SB-104/A question...

[JF]

Alexander N. Gerli, Sr. wrote:
> 
> Is the mic impedance for the SB-104 high or low? Appreciate someone
> setting me straight on that.
> Vy 73,   Sandy AC1Y


The SB-104 series need Hi-Z mics, 25K or higher, with a rating of
-45 to -55 dB. The Shure 444 unamplified desk mic is one that had
a high enough audio output voltage to work very well with the
Heathkit SB-104s (I seem to recall that some of the Shure 444
series had a base switch for selecting Hi-Z or Lo-Z, and some had
preamps).

Not all Hi-Z mics put out enough voltage to drive the SB-104s: for
example, the unamplified Kenwood MC-50 does not (it can be set for
either 50K or 600 ohm impedance) - to use that particular one you
would have to add a preamp. Back when the SB-104s were being made,
I believe Heath recommended using their Hi-Z HDP-21A desk mic, made
by Electro-Voice. Later versions may have been the HDP-121 and
HDP-242.

73
John   KE5ZB

-----------------------------------------------------------
Products bought, sold or traded here is the responsibility of the
parties involved.  This list and the City of Tempe are not responsible
for losses or misrepresentations of any kind.  Buyer beware!

-----------------------------------------------------------
This list is a public service of the City of Tempe, Arizona
-----------------------------------------------------------

Subscription control - http://www.tempe.gov/lists/control.aspx?list=HEATH
To post - HEATH at LISTS.TEMPE.GOV
Archives - http://lists.tempe.gov/archives/HEATH.html