Converting standard C & Ku Band Corotor Scalar Ring to Fit S Band Yagi

[subman]

I was wondering how hard it was to convert a standard C & Ku Band Corotor Scalar ring to fit a S Band Yagi . With the standard Chaparral Corotor II Plus C/Ku/S TRI-Bander the S Band Yagi is mounted through the Scalar ring , They seem to have removed 3 inches of Rib then drilled a hole to accommodate the shaft of the Yagi .

I was wondering how critical it was mounting the S Band Yagi , As I can cut away 3 inches of rib with the Dremel then drill a hole .

Any thoughts from any one .

 

[s-band]

Way back, I just used a dipole with reflector. It was tuned to 2.5GHz for Arabsat. I just drilled out one of the mounting holes to accept the SMA female on which it was mounted. No mods were made to the scalar. It was a bit forward of the C band phase centre but didn't make much difference at S band.

What do you hope to receive?

 

[subman]

Way back, I just used a dipole with reflector. It was tuned to 2.5GHz for Arabsat. I just drilled out one of the mounting holes to accept the SMA female on which it was mounted. No mods were made to the scalar. It was a bit forward of the C band phase centre but didn't make much difference at S band.

What do you hope to receive?

View attachment 169456 View attachment 169457

 

[subman]

Many thanks for the reply by the sound of it its not that critical where you mount the S band Yagi . I have found a original Chaparral S Band Yagi but the owner has lost the original Chaparral scalar plate so I thought with a Dremel I could cut away 3 inches of Scalar ring and mount it as original by drilling a hole the size the size of a N Connector .

As for what I will receive well Ive got access from 65 East to about 55 west so if there is some thing there I should some thing . I have a few scopes as well so in the past I just run across the belt until i find something on the scope then do a search with the receiver . Its a 3.7m Precision dish with a 36 inch Thomson Saginaw . Never had a play on S band so I have no idea what’s there .

 

[John]

Way back, I just used a dipole with reflector. It was tuned to 2.5GHz for Arabsat. I just drilled out one of the mounting holes to accept the SMA female on which it was mounted. No mods were made to the scalar. It was a bit forward of the C band phase centre but didn't make much difference at S band.

What do you hope to receive?

View attachment 169456 View attachment 169457

This new thread has got my curiosity instinct buds twitching again ..... not touched S-band searching for around twenty years or so .... SO, is it time or even worth it, to strap on my Chaparral 3650 LO Downconverter with limited range on to a spare mount onto the 2.2m lnb changer @s-band

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[s-band]

This new thread has got my curiosity instinct buds twitching again ..... not touched S-band searching for around twenty years or so .... SO, is it time or even worth it, to strap on my Chaparral 3650 LO Downconverter with limited range on to a spare mount onto the 2.2m lnb changer @s-band

I've not looked above 2.5GHz recently but I don't think that you'll get much there apart from some cellular. The LNB you have may just curl up and die given your proximity to the cell tower. When Arabsat was on S, the spectrum was very quiet, no cellular or WLAN. The only TV is in Indonesia and that's encrypted. Sirius XM has been received from mountain tops on this side of the Atlantic but you'd need an RX, preferably still subscribed. There are some Globalstar downlinks around 2490MHz but they are LEOs.

You might have a chance with ISS but I have to use a cavity filter after the 1st LNA for the system not to overload. To give an idea of the level of the problem, here's ISS nestled between cellular and WLAN (the latter is self abuse though). The max held plot is from a complete ISS pass.



If the LNB isn't deafened by other stuff, you might see something from Geo sats in the 2.2-2.3GHz range but it's all wavy lines.

S-Band (2.17-2.67 GHz) - Satellites Community

www.satellitescommunity.de

 

[John]

I've not looked above 2.5GHz recently but I don't think that you'll get much there apart from some cellular. The LNB you have may just curl up and die given your proximity to the cell tower. When Arabsat was on S, the spectrum was very quiet, no cellular or WLAN. The only TV is in Indonesia and that's encrypted. Sirius XM has been received from mountain tops on this side of the Atlantic but you'd need an RX, preferably still subscribed. There are some Globalstar downlinks around 2490MHz but they are LEOs.

You might have a chance with ISS but I have to use a cavity filter after the 1st LNA for the system not to overload. To give an idea of the level of the problem, here's ISS nestled between cellular and WLAN (the latter is self abuse though). The max held plot is from a complete ISS pass.

View attachment 169472

If the LNB isn't deafened by other stuff, you might see something from Geo sats in the 2.2-2.3GHz range but it's all wavy lines.

S-Band (2.17-2.67 GHz) - Satellites Community

www.satellitescommunity.de

Thanks for the informative reply, it's what i expected really. Gone are the good old days of yesteryear pre digital, good old analogue airborne fta downlinks etc .

 

[s-band]

Thanks for the informative reply, it's what i expected really. Gone are the good old days of yesteryear pre digital, good old analogue airborne fta downlinks etc .

Did you catch Saudi 2 or Egyptian Satellite Channel on Arabsat in late 80s/early 90s?

 

[John]

Did you catch Saudi 2 or Egyptian Satellite Channel on Arabsat in late 80s/early 90s?

Nah, can't remember doing that

 

[subman]

Glad to see got a bit of interest in S band , Well im still searching for a Chaparral Corotor II Plus C/Ku/S TRI-Band Wideband Feedhorn . I have found bits but not the whole thing .
If I cant find the whole thing then looks like dremel job just cut and drill the scalar ring .Then fit the small S band yagi Ive had to order from the states a replacement Skew motor .
I have no idea what I am going to find on S band anyway since ive got the corotor off the dish I pressure washer the dish down and greased the polar mount its done well since it was installed in 1991 . So the search is still on .

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[John]

Thanks for the informative reply, it's what i expected really. Gone are the good old days of yesteryear pre digital, good old analogue airborne fta downlinks etc .

Curiosity still pestering me ...... lashed up from a scrap Nplug bit of old cut off coax a very quick very rough but cut to frequency dipole & reflector - bunged it into the Chaparral and pointed it out of the shack window just to see what the analyser shows out of curiosity. Interestingly the Chaparral will receive signals from the signal generator from 1.950GHz to 2.7GHz - will have to throw it on the 2.2m and scan the arc to further satisfy the curiosity and then most likely take it off and put it back in the collection of other failed bits & bobs.

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[subman]

So how much activity is there on S band and what satellites are active ? In the past ive used 23 cms for packet radio nodes running 9k.6 . But have no idea what is on X band . Next problem is finding a suitable X Band LNB any recommendations since it would have to be one with a double N connector .