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

Tape Recorders

assib@imap1.asu.edu wrote:
> Hi,
> Here is a technical issue:
> I want to record a 9600 downlink on tape.

Better late than never?  15 days behind on my email.

I experimented with this and found a VCR is best.
I used a 4 head HiFi VCR.  SP speed provided the best
data recovery with about 95% and EP was like
80%.  I used a VCR at Dayton in 1997 and used
the EP because I wanted something that would
last 6 hours.  I did not try the 8 to 10 hour tapes.
The Dayton demo did good as it showed people what
a typical pass looked like. The WISP program
was requesting files and the TNC leds where blinking
away.  It looked real.

One thing the helped was building a dual op amp
amplifier with a buffer stage and amp stage with a
gain of 4 or 5.  This brought the disc. audio up
to a level the vcr liked.

I zipped up a file that saved the "state" of the wisp
program before I recorded on the VCR.  I programmed
the VCR to capture all the passes of one satellite on the
tape.  I then put wisp on the demo machine and restored
the zip file.  It was neat watching the tape playback
(esp the SP speed test) as the WISP program was requesting
files in sync with the original requests and it seemed like
there was a satellite there filling requests. The secret
is to set the computer to the same pre-recording state.
If the same information gets inputed WISP should react the
same way.

73 Eric eac@shore.net WB1HBU

Via the amsat-bb mailing list at AMSAT.ORG courtesy of AMSAT-NA.
To unsubscribe, send "unsubscribe amsat-bb" to Majordomo@amsat.org