v box dodgy or what??

[spuey]

hi,

any help on this would be great. I had a 7020 dreambox before working on disque2 . I found that certain channels were a bit dodgy, as if not tuned in. Could not figure it out so i lived with it. Recently bought a 7025 and ran another cable for dual lnb. After hours of messing around (missis wernt too happyO-no ) figured out that the boxes work fine on all channels, but as soon as i plug in the cable in the v box and try it the same channels like on the 7020 go a bit dodgy again.

So i can only conclude that when v box is in circuit it interfers with these channels (ie multivision on hotbird) .messed around with lnb settings but to no avail.

Has anyone come across this or have any idea whats wrong, ??

v box is a superteck 99 postion positioner..

cheers

 

[rolfw]

It would appear that the v-box has a high insertion loss and is reducing the signal strength to borderline. How long is your cable run from the dish to the receiver?

 

[spuey]

hi rolfw,

its about 35metres give or take. The dish is mounted on a pole at the bottom of garden.

If it is loss due to the v box how do you think the best way to overcome this?

cheers

 

[rolfw]

Well with 35m cable run and a vbox inserted, you could probably use a low output line equaliser/amp to counter the cable and insertion loss, they are quite cheap to buy.

 

[spuey]

hi,

cheers rolfw for ten quidish its defo worth a try.

will let you know how i get on.

nice one

 

[spuey]

hi,

fitted the amplifier but still the same . i put it between the reciever and v box. Is this where it should be? Although my signal is showing snr = 92 ish and Acg = 89 ish, and ber=0, so the signal should be ok?

Seems strange how the v box somehow interfears with these channels.

Anymore ideas.

cheers

 

[rolfw]

No, it goes at the LNB end, not far from the dish. ! The object is that you launch the signal at a higher level to counter the potential loss of the Vbox. If you add it after the Vbox, you have already lost the signal and have nothing to amplify.

 

[Channel Hopper]

I would borrow another LNB to try, it could be the one you have is just a little bit borderline.

 

[spuey]

hi,

this is my second lnb, brought a 0.2db twin one so i guess it should be ok. so i basically insert it in circuit as close to the lnb as possible up by the dish end then? Think i get what your saying now about the amplification of the signal! live and learn hey.

As we are having such fine weather at the minute i will give it a go tomorrow.

cheers for your help guys

 

[spuey]

hi,

have mounted this about 6 inches from lnb just to see if it worked. Altough the signal levels do seem slightly higher its still the same , certain channels like the free to air thai channel, have lower signal levels but they fine...??

I would invest in a new v box if i thought it was gonna solve the problem. So far i have changed lnb, reciever and put this amplifier in circuit. I measured the run today and its more like 40 metres than 30m. But like i said the signal strength on the reciever are both over 90 with the ber reading zero.

any idea of the next step.

cheers

 

[Channel Hopper]

Could the V-Box be installed near something that is causing interference ?

(Try wrapping it in foil for a few minutes)

 

[spuey]

hi,

this is strange. Have noticed that if i touch the outside housing of the f connectors which screw into the back of the v box the channels are spot on, if i remove my hand they go dodgy again.?? all i can think of is that by touching tham i am some how earthing them? Anyone with a bit more knowledge on this have any ideas?

 

[Prophessor]

I suppose you are talking about a diseqc motor on a v-box (?), so the signal has to do some travelling between receiver » vbox » motor » amp » lnb and back... Wouldn't a polarmount and an actuador solve the problem completly? The drawbacks are one more cable to deal with and spend more dosh on the motor and polarmount (ebay)... I think this would leave out of the equation the vbox, diseqc motor and line amp.