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2094

ZandarKoad
@comcast.net

ZandarKoad

Anon

Prodelin vs Raven dishes

(Using an HN9200 modem.)

I have a very long backstory to this question, but to keep it short:

Would using a Ka B-band LNB / Tria on Prodelin dish cause signal strengths to be much lower than expected? I was told I should get around 80 or 90, but the highest I could get was 46. I was told I needed a Raven dish. Do these two manufacturers make dishes with different focal lengths or something?

grohgreg
Dunno. Ask The Chief
join:2001-07-05
Dawson Springs, KY

grohgreg

Member

Can't speak for Raven, but Prodelin makes a LOT of reflectors. Some are Rx only, some are TX/RX. Some have higher gain than others (in the same diameter). So what you have to do is get the Tx and Rx gain numbers associated with the Raven to which you refer, then go through the Prodelin specs to see if they make a better one in the same size.

When you get the Raven numers, go here for the Prodelin numbers: »www.gdsatcom.com/vsat.php

//greg//

heeby jeeby
@verizon.net

heeby jeeby to ZandarKoad

Anon

to ZandarKoad
cant speak for b-band, im all A-band (all LHCP) in my area. but we've been told strictly prodelin antennas. thus i havent even tried a raven antenna. our signals average 70 to low 90's depending on frequency....using 9200's as you mentioned. sorry cant be of any more help.
Kaosfury
join:2011-06-27
Altavista, VA

Kaosfury to ZandarKoad

Member

to ZandarKoad
i have used prodelin in exchange of a raven and vice-versa, there is a small signal difference... sounds to me like

A. not properly tuned in.

B. you need to pull the edges of the dish in a bit.... what i am saying is... is the dish warped or mildly bent?

grohgreg
Dunno. Ask The Chief
join:2001-07-05
Dawson Springs, KY

grohgreg to heeby jeeby

Member

to heeby jeeby
I'm curious where you found circular polarized A-band and B-band satellite equipment. In my world, A-band is 0-250 MHz and B-band is 250-500 MH. And down that low, the polarization is typically linear.

//greg//

ZandarKoad
@comcast.net

ZandarKoad

Anon

This is not some specialty application. This is just a regular old residential customer who's trying desperately to get hooked up before the Jupiter systems come out. (It makes no sense, we all tried to talk them out of it, they don't want to wait, but it looks like they WILL wait because none of the hardware our warehouse has works.)

To answer your question about where I got the equipment: from the warehouse. Who knows where they got it... Maybe Satan?

I think they are using the right / left polarity terminology when in fact it's really vertical / horizontal polarity. Like, right = vertical and left = horizontal (or maybe that's backwards).

So now they are shipping us Raven dishes. I'm guessing the reflectors will come with different feedhorns... Hopefully something solves this problem. It's 100% not an alignment issue, but I don't fault you for suggesting it. I also don't believe the dish to be bent or warped, as it was very carefully handled. But I did in fact try to bend it in and out with no gain. I also played with the tilt of the dish with no gain.

heeby jeeby
@verizon.net

heeby jeeby to grohgreg

Anon

to grohgreg
greg, for lack of a better explanation, that just what i understand im working with. i have a ka tria assemby (obviously hns parts), wherin the waveguide between the feedhorn and tria must be set to Left Hand Circular Polarization (LHCP). then whithin the 9200 idu, for pointing parameters, these dont actually show a numerical frequency. we select from the dropdown, ka (a or b band). without opening a modem and looking i belive it reads "KA-ABand-A4A, KA-ABandA4B, or KA-ABand-A4C". those 3 "frequencies" are the only ones i can point and commission on. when the idu reboots after registration, system info shows a numerical frquency. problem is, i havent actually taken the time to figure out which dropdown selection is which numerical frequency.
i know that probably doesnt clear alot up, but all hns issued parts. hns trias and idus, prodelin antennas.
heeby jeeby

heeby jeeby to Kaosfury

Anon

to Kaosfury
said by Kaosfury:

i have used prodelin in exchange of a raven and vice-versa, there is a small signal difference.

i could never think of a reason it would/wouldnt work as for dish swapping. ive just never bothered to try it. which if you recall had higher/lower sqfs?

grohgreg
Dunno. Ask The Chief
join:2001-07-05
Dawson Springs, KY

grohgreg to heeby jeeby

Member

to heeby jeeby
Ah, I see the problem. The folks at Hughes that came up with that nomenclature obviously have never worked in the telecommunications field outside satcom. In the real world (FCC and ITU), use of the word "-Band" denotes a given frequency range. This is done to standardize terminology between among telecommunications specialists worldwide. See »en.wikipedia.org/wiki/Ra ··· spectrum

Hughes has apparently hijacked the A-band and B-band terminology for some kind of in-house labeling for the sub-carriers within each Ka-band beam. It would save some confusion if you'd keep that in mind when discussing "A-Band" outside the Hughes installer community.

//greg//

heeby jeeby
@direcway.com

heeby jeeby

Anon

thats kind of what i was figuring. its just hughes terminology perhaps...? i just commissioned a 9200 idu, from the parameter dropdown, it reads "AMC15-A-a4b (or a4a, a4c, then AMC15-B.......etc). wherin my selected "frequency" being the A-a4b, actually does populate the frequency 1256.5 with a symbol rate of 21.

grohgreg
Dunno. Ask The Chief
join:2001-07-05
Dawson Springs, KY

grohgreg

Member

Yeah - without actually seeing their frequency plan - it sounds like Hughes made a complete departure from the standardized ITU/FCC nomenclature, and came up with their own in-house frequency descriptors for their Ka-band sub-carriers. If true, that will be a bit confusing to techs who also install "other than Hughes".

//greg//