Homemade Conical Scalar Ring

[neljtorres]

A friend of mine here in Puerto Rico did it and gave it to me works good with NSS 806 at 40 he are the picture it's made out of a ceiling lamp:

I have a 4.5 footer offset dish a dmx 241 lnb c band with dialectric plate

Signal and quality improved over 35%

 

[Cadsulfide]

Now those are some enlightening pix!

 

[1ADAM12]

A friend of mine here in Puerto Rico did it and gave it to me works good with NSS 806 at 40 he are the picture it's made out of a ceiling lamp:

I have a 4.5 footer offset dish a dmx 241 lnb c band with dialectric plate

Signal and quality improved over 35%

Have you read about doctorofsat improved dielectric plate? Claims much improved signal over oem plate.

 

[neljtorres]

Have you read about doctorofsat improved dielectric plate? Claims much improved signal over oem plate.

Thanks for the info will check it out!

 

[Mr Tony]

very cool
Its also nice to see pics with no snow in them

 

[walrus1957]

Here is a few pics of my DMX241 with original flat scaler ring attached mounted on a 1.2 meter dish. Borrowed a small socket from my metric set and using aluminum tape attached at the 3:00 oclock position between the inside ring and throat of the LNB. The socket increased quality on the weaker signals using the Coolsat 5000 from 70% to 90+% on most C-band channels both H and V across the board and out performs the conical scalers I previously tested.

RDTV on 103W was always a weak signal for me using the 1.2 meter dish and try as I might I could never get the channel to scan in. After attaching the socket I now am viewing RDFTV with 72% quality reading.

If anyone is using a flat scaler on a mini bud, try this and you will see what I mean; reach around the scaler and place your finger between the inside ring and outside of the LNB tube while monitoring the quality level on your receiver.


Love the lamp shade conical scaler! I will have to test that one out to see how it compares to everything else I've tried.

One other note, the DMX241 has out performed the BSC621-2 and other model C-band LNBs I've tested so far. I believe the gain for the DMX241 is 70db and noise rating is 13K.

 

[Sadoun]

Very impressive. Thanks for sharing your pictures.

 

[DishDigger]

WALRUS1967,
Amazing to say the least. Out of curiosity, where did you come up with that idea:? What size socket, or is it immaterial (within reason)? Also, you stated that you used aluminum tape, but the tape in the photo is clear (I'm probably showing my ignorance here, but a little confused).

Thanks, Bill

 

[neljtorres]

very cool
Its also nice to see pics with no snow in them

Thanks Iceburg!

 

[neljtorres]

Very impressive. Thanks for sharing your pictures.

thanks!

 

[caddata]

A friend of mine here in Puerto Rico did it and gave it to me........it's made out of a ceiling lamp.......Signal and quality improved over 35%

A few points on your feedhorn:

It's not conical. Conical means cone shaped. A straight side connecting two circles- like a funnel. Look at the curved profile in the photos. What you have is a parabolic light reflector. Its shape was designed to reflect light emitted by an incandescent light bulb. The filament was located at the focal point and light was reflected outward, toward whatever you wanted illuminated by the bulb. Working as a feedhorn, it's focusing whatever electromagnetic energy hits it back to the same point where the filament was located and not into the amplifier. Correct function would be to locate the antenna probes (inside the throat of your amp) at the new focal point created by your lamp reflector. That focal point usually is about .250" inside your amp's throat (waveguide). What you've actually created is a "cassagrain feed" and the amp should be rotated 180 degrees and located at the new focal point. Most cassagrain subreflectors are hyperbolic (convex) in shape.

It's not a scalar. It has no scalar rings.

Thanks,
Harold

 

[1ADAM12]

Here is a few pics of my DMX241 with original flat scaler ring attached mounted on a 1.2 meter dish. Borrowed a small socket from my metric set and using aluminum tape attached at the 3:00 oclock position between the inside ring and throat of the LNB. The socket increased quality on the weaker signals using the Coolsat 5000 from 70% to 90+% on most C-band channels both H and V across the board and out performs the conical scalers I previously tested.

RDTV on 103W was always a weak signal for me using the 1.2 meter dish and try as I might I could never get the channel to scan in. After attaching the socket I now am viewing RDFTV with 72% quality reading.

If anyone is using a flat scaler on a mini bud, try this and you will see what I mean; reach around the scaler and place your finger between the inside ring and outside of the LNB tube while monitoring the quality level on your receiver.


Love the lamp shade conical scaler! I will have to test that one out to see how it compares to everything else I've tried.

One other note, the DMX241 has out performed the BSC621-2 and other model C-band LNBs I've tested so far. I believe the gain for the DMX241 is 70db and noise rating is 13K.

Can you post your dishes F/D?
What Socket OD and length?
What skew on lnbf?
Must the socket be placed at the 3 O'clock position?
Your dish is motorized?
Consider using Minimo's BSC-621 spacer of 1/2" between Ku and C lnbf with this socket/scalar mod?

 

[1ADAM12]

A few points on your feedhorn:

It's not conical. Conical means cone shaped. A straight side connecting two circles- like a funnel. Look at the curved profile in the photos. What you have is a parabolic light reflector. Its shape was designed to reflect light emitted by an incandescent light bulb. The filament was located at the focal point and light was reflected outward, toward whatever you wanted illuminated by the bulb. Working as a feedhorn, it's focusing whatever electromagnetic energy hits it back to the same point where the filament was located and not into the amplifier. Correct function would be to locate the antenna probes (inside the throat of your amp) at the new focal point created by your lamp reflector. That focal point usually is about .250" inside your amp's throat (waveguide). What you've actually created is a "cassagrain feed" and the amp should be rotated 180 degrees and located at the new focal point. Most cassagrain subreflectors are hyperbolic (convex) in shape.

It's not a scalar. It has no scalar rings.

Thanks,
Harold

It’s not to do with Caesarean antennas. What he has there is a corollas design. He is south of the equator and receiving circular TP’s. This design relies on the fact that when you flush the toilet south of the border the water goes in the opposite direction of here in the USA. His design is bowl shaped not parabolic.

 

[Anole]

-

 

[caddata]

......design is bowl shaped not parabolic.

There is no geometric shape defined as "bowl".

It would be impractical for an incandescent light reflector to be manufactured any way other than as a parabolic. It is a parabolic reflector with the focal point located at or near the filament of a standard light bulb. A light reflector could, otherwise, be spherical in shape and have one center point. Its efficiency would be reduced by the phenomena of "spherical aberration". I imported the photo into Autocad and found the shape to parabolic in nature, not elliptical or spherical and not emanating from one center point.

A funnel is more suitable and will work better because it is conical in shape and would direct electromagnetic energy to the small end instead of refocusing it back to the dish. Adding concentric scalar rings would improve it by blocking any extraneous energy from entering the waveguide.


Harold

 

[walrus1957]

Can you post your dishes F/D?
What Socket OD and length?
What skew on lnbf?
Must the socket be placed at the 3 O'clock position?
Your dish is motorized?
Consider using Minimo's BSC-621 spacer of 1/2" between Ku and C lnbf with this socket/scalar mod?

Here is some of the testing information I can share; I was using comercially purchased and home made versions of a conical scalars on a 76cm and 1 meter offset dish for C-band reception and seemed to out perform the flat scalar rings that came with the C-band LNBs. These dishes had f/d ratios between 0.55 and 0.58.

Once I purchased the 1.2 meter dish with an f/d ratio of 0.50 the flat scalars out performed the conical scalars and increased the signal quality an additional 10%.

And yes the 1.2 meter dish is motorized.

As to the position for locating the socket it seems to work best at either the 9 or 3 oclock position, I believe it has something to do with the oval shape of the dish.

As to the socket size, whatever it takes to fill the space of the scalar ring width. Actually the socket I choose is a little taller than the hieght of the ring but do not think that is to critical. Anything metal that fills the gap should work, be it a socket or solid metal plug.

I used a piece of aluminum tape to hold in place becuase that is what was handy, the photos I took look like its a clear piece of tape due to the fact that my scalar is covered with a clear plastic sandwhich bag to keep the snow and rain out.

As far as the skew on the LNB, it is skewed to zero mounted on the dish, the motor skews the LNB and dish for each satellite selected.

As to the LNB type used, I tried the BSC621 and also the dual output C-band GeosatPro, both spec out around 68db for gain and roughly 18K for noise figure. The DMX241 specs are slightly better, around 70db gain and 13K for noise. The DMX241 is what I am currently using in order to pick up RDFTV on 103W. Could not get the other two LNBs to keep a good signal on RFDTV. I still can not get AMGTV on 97W using the DMX241, dish is just to small and widely focused, think I am getting interference from 99W adding to the problem.

I would not count out the advantages the parobolic lamp shade might have for a 1.2 meter dish. It is shaping and amplifying the signal, focusing it back to the probes. When the weather warms up a bit I plan on testing this as well and compare the results.

One other note to make; placement of the flat scalar is critical. I found for best results the scalar is attached so that the throat of the LNB tube extends about an 1/8 inch inside the scalar ring.

My son loves TVU, I receive this channel on 87W C-band with roughly 96% quality. Using the 1.2 meter dish and this setup for C-band was my only option for TVU since they left KU band some time ago.

 

[Anole]

One other note to make; placement of the flat scalar is critical.
I found for best results the scalar is attached so that the throat of the LNB tube extends about an 1/8 inch inside the scalar ring.

Here's a relevant post on the same subject:
ACradio and flat scalar tune-up on mini-bud:
http://www.satelliteguys.us/c-band-...g-c-band-my-1-2-meter-dish-2.html#post1735458

 

[neljtorres]

Here is a few pics of my DMX241 with original flat scaler ring attached mounted on a 1.2 meter dish. Borrowed a small socket from my metric set and using aluminum tape attached at the 3:00 oclock position between the inside ring and throat of the LNB. The socket increased quality on the weaker signals using the Coolsat 5000 from 70% to 90+% on most C-band channels both H and V across the board and out performs the conical scalers I previously tested.

RDTV on 103W was always a weak signal for me using the 1.2 meter dish and try as I might I could never get the channel to scan in. After attaching the socket I now am viewing RDFTV with 72% quality reading.

If anyone is using a flat scaler on a mini bud, try this and you will see what I mean; reach around the scaler and place your finger between the inside ring and outside of the LNB tube while monitoring the quality level on your receiver.


Love the lamp shade conical scaler! I will have to test that one out to see how it compares to everything else I've tried.

One other note, the DMX241 has out performed the BSC621-2 and other model C-band LNBs I've tested so far. I believe the gain for the DMX241 is 70db and noise rating is 13K.

Thanks walrus about the lamp and tried your invention and your right with the socket I used it in one of my others c band offset dish and it improved signal and quality!

 

[1ADAM12]

Walrus1957-
Thanks for the detailed report, it goes into my "Book of Knowledge". I was thinking over my morning cup of coffee, what a ferrite might do.

I noticed with the cone scalar stack that the dish actually becomes excited at certain tuning points and the signal really takes off. However, that is only good for non motorized setups. The WSI conical scalars were some what of a disappointment.

Interesting your approach of using your fingers around the scalar. Down at the radio shop, I've watched them tuning the VHF mobile antennas with their hand and checking VSWR.

I mentioned the BSC621 in hopes that someone could confirm that Minimo's foil faced 1/2" spacer did produce good performance on the Ku side. He uses a 6' PF dish.

Anole- Thanks for adding that link, it ties it all together. Wasn't there a thread where Pendragon and acradio discuss scalars and 1.2 m dish f/d?

Neljtorres- Thanks for that confirmation. When two different setups produce good results then you know you are on to something.

Walrus1957 lives in the C Band Heartland and others will not always get the same performance gain.

It would be possible for WSI to grade their supply of DMX241 and sell of the hot performers as Black Label the way Grado does with their phono cartridges.

 

[1ADAM12]

One other note to make; placement of the flat scalar is critical. I found for best results the scalar is attached so that the throat of the LNB tube extends about an 1/8 inch inside the scalar ring.

Can confirm that another member had same results.