KU LNBF Graft onto Prodelin 1M Feedhorn

[Titanium]

The weather cooled a bit today (only 90F) so ventured into the roof to play....

Found an orphaned Muzak 1M dish on the roof of my new business location with a single polarity NJR2117HA LNB and matched Prodelin feedhorn/scalar. Had to choose a single polarity, so decided to put it to use as a fixed dish for the 103W NBC feeds.

A few weeks ago I had tested several LNBFs in place of the stock feedhorn/LNB and found the best to be the KS1PLL LNBF with the SNR reduced by an average .5dB. I then verified matching performance on two KS1PLL KU LNBFs and called it a day.

Fast forward to last Friday... Disassembled one of the LNBFs and hack-sawed off the scalar and the plastic case leaving the feedhorn extended by 1/8". I then aligned the vertical probe of the new "LNB" with the Prodelin feedhorn "0" marking and secured it in place with a bead of silicone sealant. Four days later, the silicone had cured and I recovered the LNB with the modified plastic case.

Tested the grafted PLL "LNB" against the matching KS1PLL and found a SNR performance gain of approximately 1.2dB. So in theory, the grafted KS1PLL "LNB" replacing the the NJR2117HA on the stock feedhorn/scalar increased the SNR by approximately .7dB, reduced the BER and of course, increased the Signal Quality reading on weaker transponders. The real benefits are the inexpensive upgrade to a Phase Lock Loop and providing both horizontal and vertical polarities.

Yep! A pretty good day!

 

[primestar31]

I'm disappointed this also didn't involve duct tape and wooden wedges, lol

 

[KE4EST]

Great job on the graft!!

 

[Cosmo Blatz]

The word 'steampunk' comes to mind when looking at the first picture.

 

[turbosat]

Wow, he's a surgeon too! I like it.

 

[ynnedibanez]

is the silicone strong enough to hold it permanently, or was this just to test for a little while and have fun?

 

[SatPhreak]

Once cured the silicon will hold it together.

 

[Titanium]

Nothing wiggly or loose with the mod. I live in mild weather Northern California, so I suspect the silicone would support the few ounces of "LNB" as long as the coax is secured to the arm below the drip loop. This is a feasibility test for a project that I have been working on.

I am quite impressed with the performance of the simple modification! Would highly recommend this project for anyone with a hacksaw and a tube if silicone sealant!

 

[KE4EST]

This is a feasibility test for a project that I have been working on.

Very interesting.....

 

[ynnedibanez]

sweet, maybe i'll try this on a c/ku combo lnb i have so i can have a better ku lnb on it

 

[Titanium]

sweet, maybe i'll try this on a c/ku combo lnb i have so i can have a better ku lnb on it

Doubt that it would make much difference. The problem with the C/KU combo units is not the KU LNB, it is the feedhorn cavity, which is not tuned for the KU frequencies. The KU LNB just catches what happens to make it through the crash course...

 

[Scott Greczkowski]

Brian... I would check with the guys from Titanium before doing something like that... it might void your warranty.

 

[Titanium]

My warranty was voided at birth.... LOL!!!

 

[KE4EST]

So your mother was stuck with you

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[Pixl]

Nice mod, and I like your testing data to show the improvement.
I did a similar mod a while back using a SL1P mated to a Channel Master C-120 feed. Mine too was assigned to 103w.
http://www.satelliteguys.us/xen/threads/convert-satelliteav-ku-pll-lnbf-to-lnb.309148/#post-3150895

 

[Titanium]

Nice mod, and I like your testing data to show the improvement.
I did a similar mod a while back using a SL1P mated to a Channel Master C-120 feed. Mine too was assigned to 103w.
http://www.satelliteguys.us/xen/threads/convert-satelliteav-ku-pll-lnbf-to-lnb.309148/#post-3150895

Clean looking mod! I was curious to compare a whole LNBF drilled and bolted up with the cut and grafted version. Would be interesting if it provided similar performance to the grafted unit. The LNBFs could be manufactured with pre-drilled holes or slots and a user would simply remove the stock LNBF's plastics and bolt up to a feedhorn...

 

[T4Runner]

I have this SNF-031 on a 1 meter Channel Master, also on 103W.


http://invacom.net/snf031.html





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[Titanium]

Just a wee bit of a price difference... The SNF-031 is a good performer.

A little look back at satellite history: Was the first North American distributor of their products in 2004 and promised them a market for a LNBF product that I had. Ended up partnering in development of the QPH/QPF-031 back in 05-06. Ran across one of my first SatelliteGuys posts a few weeks back where I was telling members about the new unique LNBF in development and about to be released. Unfortunately, the relationship did not have a storybook ending as the company seriously lacked integrity and we severed ties with them....

The real Invacom site: http://www.globalinvacom.com/
- all part of the long story

 

[T4Runner]

Too bad for them.



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[DK_Sat]

I all ways use J-B Weld on fixing this like that, last for ever.