A cappuccino magnezzio, - a frothy cup of wide awakeness!

Same reason I once put my fizzy magnesium tablet in my fresh cappuccino instead of the glass of water next to it JB😮 Spectacular, but not very tasty 😝

The latter is looking more like it every day Doug, (why did I just put my coffee in the fridge to heat it up !!!??)
JB

Is it the meter that's mental John?
Or us!? 😮
Doug B😎

As the sun rises in the early mordy, so the recoil of the moon---- It's obviously a mental meter Doug, as the meter goes down you know your signal is going with it 😊😁😀💡
John B

Ah! OK see what you mean - low self discharge.👍
But at least they are honest enough to warn of the drawbacks!
Should be fine for TX power though👍
BTW It's not really recommendable to charge any NiMh at more than 1A, despite what it says on the case! Fast charging shortens the battery's life, reduces the number of cycles and the maximum capacity.
Cheers, Doug

Hi Doug ,
This is the type of battery that was in the transmitter

slow drain

https://www.componentshop.co.uk/9-6v-eneloop-2000mah-aa-flat-transmitter-battery-pack.html

Hi John,
" Due to the fact that we don't charge these often, is this one of the reasons that the cells are prone to deteriorating?"
Fraid so John 🤔 I'm sure we have all had this problem some time or other.
Not sure what you mean by 'slow drain' but I'm assuming that your TX batteries are NiMh.
NiMh batteries have an irritating habit of self discharging at a rate of about 1% of capacity per day. So if we ignore them for 3 months or so they will go flat or even into so called Deep Discharge with cell voltages of 1V or less.
At this point chemical changes take place which are irreversible and create a higher resistance in the cell. The chemical change prevents it from taking charge properly and what it does take is quickly dissipated in the increased cell internal resistance when placed under load. So the cell voltage collapses ☹️
NiMh cells should not be discharged below 1.1V.
If they haven't been used for a while it is recommended to cycle them through 2 or 3 discharge-charge cycles to 'recondition' them.
This helps to reduce the infamous Memory Effect as well.
This procedure is also recommended to condition new batteries.
Any half decent modern charger should include this cycling function.

Glad to hear things seem to be working now 👍
Look forward to the Sunday trials report.
Cheers, Doug 👍

Hi there Doug
sorry for the delay in replying, your knowledge and replies are much appreciated. What I have been doing the last day and a bit is, going through my transmitters and checking all their batteries and what I have found is that I have two which are 'duff' and they are the slow drain type. Its got me thinking. Due to the fact that we don't charge these often, is this one of the reasons that the cells are prone to deteriorating? Be interesting to see if anyone else has had this problem. I am going to go back to the standard battery pack for the transmitters because I had 2 old ones in the drawer and they have charged straight up and replaced the one in the 4 channel transmitter that was duff and everything seems hunky dory now, or , seems that way - so it will be a test on Sunday to see if I get a greater range :-)

john

At 30C in the shade .... what choice do I have 😉😎

🥂🍠🍨Summer living having a blast

PS:
"Could be that some early RC xtal sets would go completely unstable with no xtal fitted"
Still got few ancient 27Meg sets kicking about so I'll try that and see what my 60Meg scope says about it! Not gonna risk my 40Meg sets though, need them for my subs 😉

Marky; my glass contains a somewhat paler liquid at the moment, an Italian Custoza white wine. Goes well with the Parma ham and melon 😋😜
😎

And a few fingers of the amber nectar in your glass Doug.
Cheers Marky

"Thought you'd make it a bit clearer ...."
Gern geschehen Old chap! 😉

Don't know of any combined signal and battery meter.
How would you know what it's showing!?

Signal strength / field strength is measured with an external antenna to give an idea of the ERP, Effective Radiated Power. Which after all is what matters to our models .
Some TX antenna systems have what are known as Through Line Power meters built into the transmission line to the antenna.
They can measure both forward and reverse (reflected) power thus giving an indication of the health and matching of the antenna. If the antenna is damaged or drops off 😮 the reflected power goes through the roof and any respectable TX would immediately shut down the RF amplifier. I often used them on ship and Naval ATC installations.
Bit cumbersome, not to mention expensive, to build into commercial RC sets though 🤔.

Could be that some early RC xtal sets would go completely unstable with no xtal fitted, with unpredictable results! Shouldn't happen given a decent quality basic oscillator circuit.
The xtal then simply locks the oscillator onto the correct channel frequency.

(Handouts will be provided at the end of the lecture!!😁)

Seeing some of the comments in the"Fishtailing" thread (which turned out to be 'Much ado about nothing'!) maybe it's time I did an update to the How To on RC gear and dragged it into the 21st century. I See that there are still some myths about interference and advantages of 2.4Ghz sets wandering about!! RFI is only half the story😉
Wishing all a strong signal and always a few fingers of water under your keels👍
Cheers, Doug 😎

Thought you'd make it a bit clearer Doug. Couldn't remember if there was a TX damage problem with the Xtal out (seemed to remember reading a caution a million years ago). Probably to do with frequency safety issue as you said, (everyones' planes twitching wildly in the pits perhaps) Was pretty sure circuit damage was possible leaving aerial down too long as it warns against it in the Futaba Manual (ie carry range test out within 5 mins or some such).
I thought the older Futaba meters were a combined signal and battery meter?
John B

Hi JB,
"Don't think you should turn on the TX without the Xtal in from memory same as not leaving on with aerial down for too long (ie range check)."

Operating the TX without a xtal should not in itself be harmful to the TX.
It will just make the output frequency unstable and erratic.
Which could cause irritation to other 40Meg operators nearby 😠

Operating with the antenna retracted (or not fully extended) can cause an impedance mismatch between antenna and output stage of the RF amp.
So called high VSWR; Voltage Standing Wave Ratio.
This causes power to be reflected back into the amp instead of radiated by the antenna, which in extreme cases can damage the output transistors.
Cheers, Doug 😎

Agreed John👍
That's exactly what the meter on your TX is showing you!
It's a Battery Voltage Meter - not a field strength meter😉
When you insert the xtal in the TX it tunes and stabilises the oscillator, the drive voltage to the RF amplifier rises and hence the current demand from the amp.
If the battery has a duff cell (high resistance?) it will collapse quickly, and the TX power output with it 🤔
Cheers, Doug 😎

Hi there
thanks for the reply; I think I may just have solved the problem - the battery pack for the transmitter looks as if it has a duff cell in it - cos when I put the battery under load out of the transmitter - the voltage dies off rapidly, even though its fully charged,. Could be the strong suspect.

Have you taken the lid off the receiver and checked the condition of the aerial wire or circuit board soldering, Had a similar problem about 20 yrs ago when using 40Mhz and found that the aerial wire had broken 1/2 way down its length, Check if it has continuity and stretch it and wriggle it around while testing. May just need a new wire as the strands are very fine and can break easily. Don't think you should turn on the TX without the Xtal in from memory same as not leaving on with aerial down for too long (ie range check). Doug's your man for that info.
TX should still have reasonable range as long as it's in the green (even slightly in the red) as that's showing signal strength. Maybe it's in the power switch, they can get a bit dodgey with age. Check the solder where the antenna TX wire clip solders to the circuit board and for any 'dry sockets' on the board (TX and RX) with a magnifying glass.
John B