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Messages - Andywragg

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16
My uBITX is still in the wrapper, but I have been assured (after waiting since 25th April) that my new enclosure from InKits (amateurradiokits.in) will be shipped tomorrow which will save me a heap of time and faffing about. Once this arrives it will be a number 1 priority to get it finished.

I've already updated the firmware on the arduino to use the CEC firmware 1.08 and I'll be adding a 6 pin mini DIN socket into the audio/PTT lines to allow easy connection of a data interface so I can work FT-8.

17
Batteries & Solar / Re: 18650 battery testing
« on: June 06, 2018, 08:42:05 AM »
Hmmmm...

Either my cells are multiplying or I was sent more then 10 batteries. I actually counted them up for the first time and I have 64 cells. I'm sure each pack was only 4S when I did the tear down, so that means they sent me 16 battery packs - go figure. More options to play with...  ;D ;D

My BMS boards are still on the boat though   :'( :'( :'(

18
Batteries & Solar / Re: 18650 battery testing
« on: June 03, 2018, 07:36:15 AM »
Thanks for the kind words Guys.

Wife has been home since Friday evening, and all is looking good so far. She's extremely well considering she almost died on the sofa/setee last Tuesday. Good job my local hospitals are some of the best in the UK for cardiac care, and I was able to spot what was occurring and act swiftly. Thank feck for my previous medic training. I realise now that I need to include some dissolvable aspirin in my IFAK supplies. 

The second batch was a success and the third batch of 8 (remember I have 40 cells (5 batches of 8) to process) is now nearing completion.

Its a slow job but so far has been yielding good results. The chargers are fairly simple to operate now I have the hang of it. I may record some video of the next batch being processed now I have a bit more time on my hands.

19
Batteries & Solar / Re: 18650 battery testing
« on: June 01, 2018, 04:57:15 AM »
Thanks Joel.

There's a good chance she may be allowed home today. Fingers and toes crossed.

20
Batteries & Solar / Re: 18650 battery testing
« on: May 31, 2018, 11:47:25 AM »
The first batch of 8 cells completed Yesterday, or maybe the day before - this week has been a blur as my wife had a heart attack Tuesday evening, so I've been shuttling to/from the hospital since.

All cells are usable and are giving me between 2100 and 2300mAH,  all with internal resistance below 150.

I have another batch of 8 on test now. I'll test all 40 cells then group them based on capacity and internal resistance. My BMS boards have yet to arrive, the slow boat from China must be taking the long way around.

21
Batteries & Solar / Re: 18650 battery testing
« on: May 29, 2018, 02:45:39 AM »
Yeah I saw that product as well.

The Opus chargers arrived on Friday, but I've been away at a bushcraft meet over the weekend so didn't get chance to have a look at them.

I put the first 8 cells on the chargers yesterday. Some cells were below 3v but above 2v and the chargers still charged them to 4.2v irrespective. They are current undergoing a 3 cycle test since yesterday. I'm using the default 500ma charge and discharge rates, so a complete test takes around 27 hours.

The cells are 2800mah nominal based on the markings on the cases and the sleeve/ring colours. I'm already seeing capacity of over 2100mah for most cells.

22
Radio Reviews, Questions and Comments. / Re: Got my 1st CW rig
« on: May 23, 2018, 01:55:35 AM »
That's a real bargain, well done.

23
Antennas / Re: Mounting Antenna for NVIS vs DX operation ?
« on: May 18, 2018, 05:24:06 PM »
Hi Gil,

The design I'm using is a Ham design, based on the military version. Its actually from DXEngineering (see my link earlier). To be fair I was only there, set up  for about an hour before it started to rain, so chances are with a bit more time on station I would have probably got a contact.

The FT-817 that I had on loan has now gone back to the owner and he's traded it for an FT-897 so my /P activities are somewhat curtailed until I can get my uBITX finished, and I'm still waiting for the case to arrive, or even be shipped. Alternatively I could go /P with the FT-450 and operate from the car but that would mean dismantling the shack.

24
Antennas / Re: Random wire antennas and tuners
« on: May 18, 2018, 05:12:37 PM »
I saw the other post earlier during my lunch break.

I'm assuming you haven't done this already...

The first thing I would do is take the wires off the "bobbin" PCB and using a multimeter  (set to check continuity) check the continuity between the BNC Outer and counterpoise bolt, and the BNC inner and the main radiator wire bolt. Also check for shorts across the BNC outer and inner. Do this in ALL switch positions, as you may have a faulty switch or you could have a dry joint on one of the toroids. I normally do these checks as part of the build.

Once you have verified the continuity of the PCB check the continuity of the wires, mainly the main radiator wire, but also the 4 counterpoise wires. Do the same check with your Coax feeder (Inner/outer/short test).

Lastly check your radio and tuner with a dummy load.

I scratch built mine and its pretty damned good for a homebrew antenna. No tuner required on any of the bands. And all I did was copy the QRP Guys schematic in the manual. But until I'd got the meter beeping on everything but the short tests I didn't hook it up to the radio.

Hope this helps

Andy


25
Antennas / Re: Mounting Antenna for NVIS vs DX operation ?
« on: May 14, 2018, 07:24:48 AM »
Nice link Andy, something g like that could be made up, rolled around your support mast and be slung in the car, ready made to guy out.....

I wonder what itís also like for dx when pushed up higher - and the wires are more vertical ?

This is me testing it out the other weekend.


https://youtu.be/ZsOppHCRH08


26
Batteries & Solar / 18650 battery testing
« on: May 11, 2018, 08:48:04 AM »
So off the back of my 18650 bulk purchase, i thought I'd better get some means of testing them.

First of all I ordered one of these;

https://www.ebay.co.uk/itm/Battery-Capacity-Meter-Discharge-Tester-18650-Li-ion-Lithium-Load-Resistors-UK/122484972541?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649


It came the other day, and I havent had chance to use it yet, but I kind f had a WTF moment when I thought about how long it would take me to process 40 cells using this device.

I also thought about how to charge them to enable the tests. I do have a number of the individual cell chargers that you get with the cheap ebay flash lights. I also have on of of the Xtar smart 2 cell chargers but that has developed a problem where only one cell charges.

I looked a couple of videos from guys that are processing a good number of cells and they are using the Opus BT-C3100 charger and tester.  So I've got a pair of them (the V2.2 version) on order from GearBest. This will allow me to test 8 cells concurrently, and also allow me to charge other cell types and chemistrys (secret switch inside alters the max charge voltage).

https://www.gearbest.com/chargers/pp_174044.html?wid=1433363

Obviously at some point i need to consider the solar aspect but this will do for the QTH. Once the chargers arrive I'll get busy testing the cells out and keep you posted.

27
Batteries & Solar / Re: Salvaging old Notebook battery
« on: May 10, 2018, 02:33:11 AM »

Anyway, if your cell wont load because the Voltage is too low, attach it parallel to a charged cell for few seconds and then put it in the regular charger again. Saw that on yt, seems to work.

Via TapaTalk

You don't really want to do this as without any load between the cells, you could end up toasting both cells. Use a resistor to throttle the in rush current.

28
Batteries & Solar / Re: Salvaging old Notebook battery
« on: May 08, 2018, 08:51:22 AM »
Cell voltages recover slightly when you take the load off.

Mine have arrived, not so many as I expected the ones in the advert appear to be the kind with 6-8 cells, as these packs are all 4S (rather than 3S2P or 4S2P) but they all appear to be at least 2500mAH so as long as I can get some usable ones out of them I'll be happy.

I'll take a look at that BMS.



29
Batteries & Solar / Re: Salvaging old Notebook battery
« on: May 08, 2018, 03:44:39 AM »
My Job lot of 10 HP laptop batteries arrives today. Let's see how many good cells I can harvest.

BTW what BMS is that?

30
Technical Corner / Re: Armored BitX40.
« on: May 02, 2018, 08:47:01 AM »
I've had the uBITX for some time now (just over a month) and have yet to make a start on it. I bought a pair of those plastic Banggood enclosures dirt cheap and started to mark out ready for cutting the face and rear plates but have had a change of heart and ordered one of those custom uBITX cases from India. $60 inc shipping for a pre-cut/drilled, painted grey aluminium case (note the correct spelling folks LOL) with a few extra connectivity bits included. Hopefully it should be here within a fortnight.

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