MiniBUD: do I have a bad C-band LNBF or...?

[Pepper]

I've been experimenting again with the one-meter channel master dish. I've yet to capture my first C-band signal and growing anxious for one.

I accumulate parts over time. About 6 months or more ago I got a B1SAT stacked LNBF. I fashioned a home-made conical scalar/feedhorn out of an old thick cardboard political sign covered in aluminum foil. I got nothing. Not really surprised, just another "can it be done" project I failed at.

Christmas brought a nice new shiny conical scalar ring. I've not yet figured out the right/best way to put it all together on this particular dish, but thought I should at least be able to get "something" with enough patience and tinkering. Using compass, inclinometer and dishpointing website to begin with, point, blindscan, adjust, repeat as necessary. Again, no luck at all.

At one point I got tired of doing things blindly and decided to dig out my little cheapo signal meter and see if I could find a signal. I discovered something interesting at this point - even if the LNBF is pointed directly at the ground, it pegs the meter - even if I adjust the sensitivity all the way down.

This behavior makes me think my problem is one of the following:
- the meter is no good with C-band signals (same intermediate frequencies, should not make a bit of difference should it?)
- this type of LNBF generates a lot of "noise" that makes the meter go wacky
- the LNBF is shot and I need a new one
- the meter is shot (guess I should try it on the working Ku band stuff to rule this out)

Any other ideas for me to try here?

 

[Lak7]

What meter are you using?
I have read that when using the SF95? style Meter for C Band, you need to keep it behind the Dish.

What size is your Dish?
Can you mount a Ku LNB and Lock a Signal?
Do you have the receiver setup properly for a Back Stacked LNB?

 

[Corrado]

In my experience it's normal behavior for a small meter in front of a C band reflector to peg the meter. That tells me the LNBF is probably OK. Why not point the dish first on a known Ku feed. Once that's done switch over to C band and go from there.

If using the bandstacked LNBF what LO frequency is being used?

 

[guapoharry]

... I discovered something interesting at this point - even if the LNBF is pointed directly at the ground, it pegs the meter - even if I adjust the sensitivity all the way down....

Isn't that the whole reason for using scalar rings...? to shield the LNBF from noise/signal reflected from the earth...:up

Some one correct this if mis-stated, please... An other way to describe it is that scalar rings block everything but the signal reflected from the dish from going in to the LNBF...

 

[Pepper]

It's one of those cheap meters, I think I paid like $3 on ebay for it.

If I physically cover the end of the LNBF with tinfoil, it should register no signal at all on the meter, right?

I think the "point it with Ku first" idea holds promise. Once I do that, in theory my adjustments should be with the LNBF, scalar and how it's physically mounted, not with the dish pointing itself.

I was using 5150 for the LO if I remember correctly.

 

[Mr Tony]

on the bandstacked LNB there are 3 options

the legit setup is 5150/5750 but if you dont have that option
use 5150 then all H polarity will be 600mhz lower than the "published" frequency (vertical would be "normal") or
use 5750 then all V polarity will be 600mhz higher...H would be "normal"

 

[guapoharry]

Is it a meter like this with an adjustment knob?

 

[Pepper]

yep, just like that one, but black non-branded.

 

[meinename]

yep, just like that one, but black non-branded.

Trying to peak C band on a 8.5 solid aluminum and a 10.5 foot mesh had the same results with those meters.
Squeal On or Off.
Even with 50 foot of cable with me and the meter due WEST 45 feet from the dish
The meter is not precise enough for digital when you otherwise have good Idea where you are aiming. Such as:

• on your own property
• Dish was aimed on a H-H motor via USALS
• dish was peaked on Ku and you're just swapping LNBF's

With Ku, both FSS and DSS, that meter can be a help getting started until you start memorizing where things are.
That is once you get use of the knob down for peaking.
The SF-95 meter is/was my best friend in getting started on offset LNBF's

I haven't used it much in the last year but it stays in my tool-bag for satellite.

Depending on how much rain comes in the morning I'm going to grab the spare BSC-621 and See if I can get a 2/3 FEC C-band on a .9 and a 75e later this week