[Date Prev][Date Next][Thread Prev][Thread Next] - [Date Index][Thread Index][Author Index]

Re: ARR vs SSB preamps



Hello Karl,

As I recall the SSB SP-7000 can use 13.8 VDC supplied on the RF output
line.

A DC injector like the SSB DCW-15 will provide sequencing and DC
injection onto the coaxial line used as the mast mounted preamplifiers
output. The DC injection is done in the shack.

The real issue is the radios ability to supply enough current
to the preamplifier. Most manufacturers do not provide the details
on the maximum current available for injection onto the RF line
to the preamplifier. DC power is only needed in RX mode.

DC power is needed for the actual preamplifier AND the coaxial relays
that
bypass the preamplifier on TX. Some bigger relays can require as
much as 190 mA each relay. I avoid using the radio to supply DC on RX.

Having used the Yaesu FT-736R, FT847 and the ICOM IC-910H, I always
use external DC injectors AND an external sequencer. All of my mast
mounted 
preamplifiers use a hard keyed PTT, gnd to TX.

Now, if the manufacturers provided 2 amperes from a relay contact
closure on RX,
I would use the radio for mast mounted preamp power.

Most mast mounted preamplifiers will allow RF sensed "soft" keying of
the
preamp bypass relays, but the relays will handle more RF power with
hard
and sequenced keying.

ARR makes a nice sequencer, DEM Inc makes another.

The DC voltage input range is usually broad enough to cover the
standard spec of 13.8 VDC +/- 15% or 11.7 to 15.9 VDC.
Most preamplifiers use an internal voltage regulator.

Stan, WA1ECF  FN41   Cape Cod, MA 





Karl Sandstrom wrote:
> 
> Thanks to all the replies concerning my previous post.  They are all
> appreciated.
> 
> I am still undecided but am leaning a little toward SSB.  However, there is
> a piece of data I'm missing.  Does anyone know the voltage and current
> requirements for the SSB SP-7000??
> 
> I have put a VOM on my IC-910 and it registers 12VDC not 13.8VDC.  I suspect
> this may have been one of the problems with my Mirage KP-2 which requires
> 13.6VDC.
> 
> Thanks again & 73 for now.
> 
> Karl R. Sandstrom, K5MAN
> Greenwell Springs, Louisiana
> k5man@arrl.net / k5man@amsat.org
> 
> ----
> Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
> To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org
----
Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org



AMSAT Top AMSAT Home