Loss of FPV image quality - a cure that works for me more times than not!

[Bad Raven]

FPV Gear has improved over the last couple of years, and it is easy to assume that your older gear, now less well performing, looks low due to that general improvement, or maybe is due to ageing of CCD/CMOS, etc.

Over the past two years I have experienced and been around when others have experienced poor image through to total loss of image.

In most cases I have found that image improvement (or "reinstatement/repair!") can be gained by making sure that the connections are sound and low resistance.

These include:-

1. Connectors to VTX
2. Connectors to Camera
3. Switches used to change VTX output power (commonly single pole 25/200mW)
4. Channel/Band/Power button

These are rarely gold plated contact, and over time they oxidise or get ingress of dust/dirt/damp.

I have found the following works in MOST cases:-

Ideally using an evaporating contact cleaner, and with NO POWER ON, spray into the connection and immediately disconnect/reconnect a few times. Field repair can often be done by just disconnection/reconnection, the contact surfaces rubbing each other cleaner.

Do NOT use WD40 or any silicone contact cleaner, only fully evaporating IPA based ones like RadioSpares. (an aerosol lasts many years, I have one in use now over 20 years old!)

Do NOT put the power back on until you are sure that any contact cleaner has evaporated!

I have used this successfully on all the four issues above, curing total cessation of image, extreme noise, venetian blinding, etc.

I have also used it on Transmitter stick potentiometers on older Tx where they have gone jittery, usually they go erratic near end of travel where the dirt and carbon track residue collects.

In this latter case I remove the battery, wash the pots out with a short but strong blast of liquid through the gap where the PCB exits the pot case, working the sticks and draining the liquid away from PCBs etc onto a tissue to see the effect, then leave overnight with battery out to ensure dry.

I also use this method successfully on Blade type linear helicopter servos, holding it so the dirt washes out away from anything else onto a tissue so I can see how cruddy they have become!!



 

[hoverfly]

I have been using Servisol for many years, shop around for the best price.

https://stage-gear.co.uk/servisol-701-100uk-switch-cleaner-super-10.html?utm_source=google_shopping&gclid=EAIaIQobChMIr_jfq9ix4gIVxrDtCh1BnwLiEAQYAiABEgI1MfD_BwE

[mo_miah]

I remember seeing something by JB or Mr Steele about SMA connectors having a finite number of mating cycles as the pin wears out, wiki says they are designed for X number of mating cycle under X amount of torque
the antenna on my tx and quad always remain in place but the ones on my googles i take off after each session, i only fly once a week so will take a few years to wear them out but for daily flyers i could see this as being an issue

[hoverfly]

Lots of people use adaptors  that are left on the goggles, when it wears out the goggles socket is still in good condition it also gives a bit of clearance between the patch antenna and the clover leaf / pagoda antenna.

[Bad Raven]

Lots of people use adaptors  that are left on the goggles, when it wears out the goggles socket is still in good condition it also gives a bit of clearance between the patch antenna and the clover leaf / pagoda antenna.

True, and they have their place, but factor in that every friction contact connection adds resistance, no matter how good, so adding an adaptor or converter or 90 degree changer is always worsening the signal no matter how minimally when new and adding another fail point to go High Resistance. Normal engineering principles still apply, keep it simple, fewest parts and joints possible.

It is interesting though that near all the experience of signal quality loss I have seen has not come from antennae connection, but from power connection or camera to VTX wiring HR.