ad: vanity

Interference on free view box

Discussion in 'RFinderPi - Open Source radio interface based on R' started by G0VQY, Sep 15, 2017.

ad: L-HROutlet
ad: l-rl
ad: HRDLLC-2
ad: abrind-2
ad: L-Geochron
ad: Left-2
ad: Left-3
ad: L-MFJ
ad: MessiPaoloni-1
  1. G0VQY

    G0VQY Ham Member QRZ Page

    One of the TVs in our house has a Free View box attached to it giving three channels and also allows the recording of programs. However, when watching TV programmes through the box my HF will often cause interference by freezing the picture whilst I am transmitting. What is the best way to solve this problem. I'm not sure what is picking up the RF, the power cable or the TV aerial cable. Thing is, if you watch television directly from the aerial signal television then no interference occurs, it seems that this box is picking up the RF.
  2. G0GSR

    G0GSR Ham Member QRZ Page

    I would guess the aerial downlead is picking this up as its by far the longest.
    Try wrapping as many turns as possible of the aerial cable around a large type 43 ferrite toroid, installed close to the Freeview box.
  3. KA9JLM

    KA9JLM Ham Member QRZ Page

    Are you using the RF modulator out on the box ? How does it feed the TV ?
  4. G3YRO

    G3YRO Ham Member QRZ Page

    Why only three channels? You can normally get about 70 channels on Freeview these days.

    (for you guys in the USA, Freeview is the British terrestial Digital TV service . . . broadcast around 500MHZ . . . and as the name suggests, Free! No Satellite Dish or Cable required)

    I've found these boxes pretty good in terms of RF immunity. I only have a TV aerial in the loft (so the received signal isn't brilliant) yet still have no issues on any of the HF Bands, even running a Linear Amplifier.

    You could try fitting a normal UHF Braid-break filter . . . these are still available, and were widely used in the Analogue UHF TV days, as you sometimes could see slight patterning.


    I used to always have one in my TV Aerial feed. But since Digital TV it's not necessary, as slight interference doesn't usually affect the picture - it's only if the breakthrough is so strong that it can't get the signal at all.

    Roger G3YRO
  5. KA9JLM

    KA9JLM Ham Member QRZ Page

    In the day, The Moonraker was the bomb in the U.S.

    You could blow smoke on 11 meters. Even with legal power limit.

    I get over 100 channels, And only 1 worth watching. PBS
  6. G3YRO

    G3YRO Ham Member QRZ Page

    No wonder this guy hasn't replied . . . just noticed that his post was last September !

    Roger G3YRO
    G0GSR and KA9JLM like this.

Share This Page