my feed is installed!

[linear_shift]

The feed for my RT is in! Pictures, and a little blurb about it here:

http://kmradioastro.blogspot.com/

I've actually gotten some good results with it as a TV antenna. As
soon as Jan's noise source gets here and I build my receiver, I'll
test it and get some quantifiable results. Hopefully its good to go
for RA. *crosses fingers*

Keep your ears on the sky, ls.

[James H Van Prooyen]

Very impressive!  I would like to hear more about your receiver...   Jim Van Prooyen --- On Sun, 12/7/08, linear_shift <linear...@yahoo.com> wrote:

[linear_shift]

Jim,

The receiver is a TV tuner receiver kit made by MTM Scientific:

http://www.mtmscientific.com/tuner.html

However, there is a problem that came to my attention with this kit
regarding the IF output of the tuner, that was brought to my attention
by a Mr. Joel Gonzalez:

http://www.backyardastronomy.net/radio_telescope.html

I have yet to build mine, so I cannot say it is the tuner design at
fault, that he just got two bad tuners, or was a in a bad batch that
MTM got. I actually got mine before Joel's so I am hoping mine will
work ok. He uses the AFT pin on the tuner (the S-meter voltage) to
take TPR measurements. It works fine, but I need the actual AC
component (the 6 MHz chunk downmixed to 45.75 MHz) for spectral line
measurements and SETI.

Regarding the downconverter, I will likely use compenents from
MiniCircuits to build it:

http://www.minicircuits.com/

I might though, if I can ever get the money together to buy it, I will
get the RAS downconverter:

http://www.radioastronomysupplies.com/show_detail.php?item_id=12

The LNA is going to be the RAS 610 MHz LNA

http://www.radioastronomysupplies.com/show_detail.php?item_id=14

with some custom stuff done to it, and the filter is going to be made
by a company in Canada:

http://www.tinlee.com/bandpass_filters.php?active=1#CF7 (the CF7)

The narrowband part of the receiver is going to simply be a NE612
mixer and a PLL oscillator downconverting the 45.75 MHz + 6 MHz IF for
reception by image cancelling direct conversion HF receiver (like the
SoftRock 40) and then to a computer sound card for DSP analysis by a
program called baudline:

http://www.baudline.com/

Anyway, for now it is going to simply be the tuner kit and a 10-bit
(later 12-bit) serial port PIC A/D converter:

http://www.mtmscientific.com/atod.html

There won't be an LNA or filter at first, as I can't afford either at
the moment (I hope to have those by the end of January, not promising,
just hoping ;) ).

Keep your ears on the sky, ls.

On Dec 7, 7:55 pm, James H Van Prooyen <g...@sbcglobal.net> wrote:
>
> Very impressive! I would like to hear more about your receiver...
>
> Jim Van Prooyen
>

> --- On Sun, 12/7/08, linear_shift <linear_sh...@yahoo.com> wrote:

[Rodney Howe]

SARA,

 

A couple of questions, perhaps some have worked through these problems. 

 

I'd like to do a drift scan of the sky a degree or couple degrees at a time (depending on beam width).  I'll be capturing data in a few 10s of millisecond interval, then average data for each minute.   I'd like to calculate the LSR for each minute timestamp.  These will be continuum data.

 

1).  Should I do a rolling average for each ms observation, or point average at the end of each minute?

 

2).  Is there open source code for calculating LSR? (FORTRAN)

 

3).  Do I have to read ephemerid files for the galactic LSR calculations of RA and DEC? 

 

 

Rodney