Improving DX6 and DX7 battery runtime.

[phockzie]

This is an interesting mod which can double the battery life of DX6 and DX7 batteries.

Improving the runtime of the Spektrum DX6

It involves replacing the voltage regulator inside the transmitter with a more efficient switch mode regulator.

EDIT:
PLEASE NOTE -
This will probably invalidate your warranty and possibly your BMFA insurance.
Also ...

...can also weaken frequency.

any modification to the tx will invalidate the type approval for the set.

[Brian Gifford]

Interesting! I notice it's the DX6, not DX6i, but thanks for a very useful link.

[Aidi]

This has been discussed before. Where as the modification will likely improve battery life, it can also invalidate your BMFA insurance.

If you were to have an accident and your TX was inspected and found to have been "modified" i dont think it would go down to well.

Better of biting the bullet and buying a second battery IMO.

Rgds
Aidi

[phockzie]

If you were to have an accident and your TX was inspected and found to have been "modified" i dont think it would go down to well.

Fair point.

Would this also apply to modifying a DX6i to use welded cells, as you are essentially modifying the power supply for the unit?

[Aidi]

You could argue the point on batterys till the cows come home.

I know lots run Lipo's in DX7's and various other NiMh packs.

[phockzie]

You could argue the point on batterys till the cows come home.

I havn't got the time or inclination

[tourerjim]

Read on another forum can also weaken frequency.

[0h5h1t]

any modification to the tx will invalidate the type approval for the set. the owner will become liable for re type approving the set and therefore will not be covered by bmfa insurance until the set has been tested and type approved.. this can land the owner/operator in a whole heap of doodoo's... not worth the risk really. I don't think higher capacity nimh cells are a problem on there own tho but don't know the bmfa standing on lipo cells.

[t43er]

Check out the threads in helifreaks. They have a lot of mods for the tx over there but bear in mind any mods will void your warranty! Do at your own risk I guess

[moyesboy]

Surely the type approval applies to the transmission characteristics and if the mod doesn't effect them then there should be no problem. I suppose there is some risk that if you put more volts in then the RF might change but it shouldn't because it is regulated. more liekly too many volts will blow the regulator and the Tx will stop working.

Some folks using ;3 cell lipos are charging them only to 80% to avoid the full voltage - in fact a lipo will last more cycles if it is only charged like that.

The DX7 tx is already more efficient and lasts longer on a std tx battery than most 35Mhz sets.

Using a switch mode power supply might have a chance of upsetting the rf electrics in the same was as switch mode BECs are prone to interfere with receivers more than smooth linear regulators. To bo honest I can't see the point. Just buy an extra Tx battery for a tenner instead!

With NiMH packs the main loss of capacity is the charge leakage meaning when you leave it a few days it needs charging again. I just fitted a vapex instant pack (retains 80% charge after a year they say) to my DX7 and took it away for almost two weeks ran an averge of two packs through my 450 each day and it never needed charging. So I recommend this solution as the least hassle and risk.

I put a cyclic ring on my TX and some sticky tape round the plastic antenna base where it cracked, fitted an offset neck strap attachment and a sticker with my name. Is my insurance invalid?

[Aidi]

I really dont think that things like Cyclic rings and neck strap offest bracket are in the same league as soldering an item which "could" effect the electronics of the unit, and subsequently cause a problem to other circuitry.

putting a lipo into a unit designed for a nimh could be debated, but i would say you are pretty safe.

Think of it from this point of view. You dont invalid your car insurance if you put on new tyres after the factory fitted ones have worn out. As long as the rating of the tyre is correct for the car you are ok. Chip your engine or alter the ECU and you dont declare it to your insurer... see if they pay up if you have a prang.

I guess you could approach BMFA and let them know you are going to mod your TX.. I can probably guess what the reply would be!!