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Hi guys Yesterday I Installed a homebrew 3S2P li-ion battery pack into my ubitx cabinet Had planned my cabinet for the right space & fit Now I can carry my ubitx for outdoor? action Next I am building a small SOTA atu Happy home brewing Best 73 Pop VU2POP
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Dear Pratap jee,
Your power inside is really welcome .
?One could take out the rig to field, with some end fed or a fold-able vertical antenna and used for an hour.?
Other mods are curiously awaited. Being a QRP, perhaps you can use PVC gang caps.?
Regards
sarma
vu3zmv
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Sarma, ?????????????? Look up G0POT for his efhw aerial and vk3 ye for his atu..Regards Dave.
On Mon, 15 Apr 2019 at 07:53, MVS Sarma < mvssarma@...> wrote: Dear Pratap jee,
Your power inside is really welcome .
?One could take out the rig to field, with some end fed or a fold-able vertical antenna and used for an hour.?
Other mods are curiously awaited. Being a QRP, perhaps you can use PVC gang caps.?
Regards
sarma
vu3zmv
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End fed 1/2 wave is a voltage fed antenna Sarma ji, there might be more then kilo volts present even with QRP at end of coil... Therefore thin PVC variable Gang Capacitor won't help...
Sarma, ?????????????? Look up G0POT for his efhw aerial and vk3 ye for his atu..Regards Dave.
On Mon, 15 Apr 2019 at 07:53, MVS Sarma < mvssarma@...> wrote: Dear Pratap jee,
Your power inside is really welcome .
?One could take out the rig to field, with some end fed or a fold-able vertical antenna and used for an hour.?
Other mods are curiously awaited. Being a QRP, perhaps you can use PVC gang caps.?
Regards
sarma
vu3zmv
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I learnt another point today. Thanks Saneep jee
End fed 1/2 wave is a voltage fed antenna Sarma ji, there might be more then kilo volts present even with QRP at end of coil... Therefore thin PVC variable Gang Capacitor won't help...
Sarma, ?????????????? Look up G0POT for his efhw aerial and vk3 ye for his atu..Regards Dave.
On Mon, 15 Apr 2019 at 07:53, MVS Sarma < mvssarma@...> wrote: Dear Pratap jee,
Your power inside is really welcome .
?One could take out the rig to field, with some end fed or a fold-able vertical antenna and used for an hour.?
Other mods are curiously awaited. Being a QRP, perhaps you can use PVC gang caps.?
Regards
sarma
vu3zmv
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The transformer of an EFHW? matching network matches the 50 ohm transmitter
to an expected impedance into the wire of between 2500 and 3000 ohms.
Power is Volts*Amps, or Volts*(Volts/Ohms).
At 5 Watts of RF power,? ? 5watts = Volts*Volts/3000ohms,? ?therefore? Volts = sqrt(3000*5) = 122 Volts RMS.
At 100 Watts, it's still around 548 Volts RMS, not yet kilovolts
The polyvaricons are rated for something around 100 Volts:
? ??
Generally, you can press a polyvaricon somewhat beyond 100 Volts.
A polyvaricon works at 5 Watts for an EFHW, though?an air-variable cap would be a better choice.
If an air gap does arc over, it will self-repair once the ionized air circulates out.
And an air gap capacitor has a higher Q, and thus lower losses.
The qrpkits Sota Tuner successfully uses a polyvaricon:in an EFHW tuner:
? ??
They claim a max of 5 Watts CW, 10 Watts PEP.
On 10 Watt peaks, that would be? sqrt(3000*10) = 173 Volts RMS.
Perhaps they are more concerned about heating than they are about arcing?
Anything other than a resonant EFHW will be lower impedance,
and thus lower voltages across a tuning capacitor.
Jerry, KE7ER
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On Mon, Apr 15, 2019 at 12:33 AM, Sandeep Lohia wrote:
End fed 1/2 wave is a voltage fed antenna Sarma ji, there might be more then kilo volts present even with QRP at end of coil...
Therefore thin PVC variable Gang Capacitor won't help...
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My end-of-the-world build has a kit type bulit into the faceplate and it seems to work OK. I added two switches to switch the two variable caps in or out independently which seems to help in some cases to add or subtract in that way. I haven't logged contacts on that build as of yet though I haven't been out with it, either.
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Yes, and one can score some nice LiPo cells from a cordless drill?battery pack?and get a charging controller for the intended voltage (12v, 16v, etc) on eBay with separate leads to sense each 4v step of the battery pack for balanced charging.
Ted
K3RTA??
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18650 cells from laptop batteries.? I'm planning on using this to power my uBitx.? 4S3P pack I just built. I haven't sealed it all up with Kapton tape yet.??
Yes, and one can score some nice LiPo cells from a cordless drill?battery pack?and get a charging controller for the intended voltage (12v, 16v, etc) on eBay with separate leads to sense each 4v step of the battery pack for balanced charging.
Ted
K3RTA??
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For a small pack with limited current, Turnigy makes a ready-built protected 2.2Ah pack for $25
Especially for newer builders, this might be easier than a DIY pack with protection.
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Yes, I put one of these inside my ubitx20 rev 5.1 (tied down with
velcro strips) and it works well.? The battery is fairly compact
and comes with its own charger that has a jack that fits the
Radio. Only issue is I noticed some RF noise when the charger is
on (but didn't try putting on any "snap on" ferrite chokes to see
if that might help).
Rick KN6KB
On 4/16/2019 9:27 AM, KE0GYC wrote:
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Show quoted text
For a small pack with limited current, Turnigy makes a ready-built
protected 2.2Ah pack for $25
Especially for newer builders, this might be easier than a DIY
pack with protection.
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I have a 4.5ah 11(ish) volt battery I may use.. do you have a voltage regulater you use to maintain 12 volts as the battery discharges?
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Rick:? Web site doesn't say it comes with charger--how does one charge it if it doesn't?? Seems like it might fit my BITX 40.
On Tuesday, April 16, 2019, 11:28:54 AM EDT, Rick Muething <rmuething@...> wrote:
Yes, I put one of these inside my ubitx20 rev 5.1 (tied down with
velcro strips) and it works well.? The battery is fairly compact
and comes with its own charger that has a jack that fits the
Radio. Only issue is I noticed some RF noise when the charger is
on (but didn't try putting on any "snap on" ferrite chokes to see
if that might help).
Rick KN6KB
On 4/16/2019 9:27 AM, KE0GYC wrote:
For a small pack with limited current, Turnigy makes a ready-built
protected 2.2Ah pack for $25
Especially for newer builders, this might be easier than a DIY
pack with protection.
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I followed KEGYC's link into Amazon for the Turnigy lipo 11.1v 2200mah 1.5c battery pack, see this question and answer:
Question: Does it come with a charger? Answer:? ?come alone without charger; No you will need to get a proper lipo balance charger; Does not it come with a charger.
So it does not come with a charger.
Needs a "balanced charger", they generally cost twice as much as this $22.99 battery pack.
The Turnigy webpage on chargers looks like gibberish using this ChromeOS laptop:
??http://www.turnigy.com/chargers/
Any recommendations on a suitable charger for this battery pack?
Jerry, KE7ER
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On Tue, Apr 16, 2019 at 08:28 AM, Rick Muething wrote:
Yes, I put one of these inside my ubitx20 rev 5.1 (tied down with velcro strips) and it works well.? The battery is fairly compact and comes with its own charger that has a jack that fits the Radio. Only issue is I noticed some RF noise when the charger is on (but didn't try putting on any "snap on" ferrite chokes to see if that might help).
Rick KN6KB
?
toggle quoted message. . .
?
On 4/16/2019 9:27 AM, KE0GYC wrote:
For a small pack with limited current, Turnigy makes a ready-built protected 2.2Ah pack for $25
Especially for newer builders, this might be easier than a DIY pack with protection.
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Sorry... I thought this was the same one I
purchased.
Mine was:
$~24, Prime Shipping, With charger. It claims 3000 mAHr but it is
probably closer to 2400 or so based on some comments. It has a
convenient disconnect switch and has a pretty well regulated 12 V
output.? Charger is rated at 12.6 v Out at 500ma.? (100-240 VAC
input). The battery has built in protection and regulation I
believe.
Rick KN6KB
On 4/16/2019 12:25 PM, fejohnso via
Groups.Io wrote:
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Show quoted text
Rick:? Web site doesn't say it comes with charger--how does
one charge it if it doesn't?? Seems like it might fit my BITX
40.
On Tuesday, April 16, 2019, 11:28:54 AM EDT, Rick
Muething <rmuething@...> wrote:
Yes, I put one of these inside my ubitx20 rev 5.1
(tied down with velcro strips) and it works well.? The
battery is fairly compact and comes with its own
charger that has a jack that fits the Radio. Only
issue is I noticed some RF noise when the charger is
on (but didn't try putting on any "snap on" ferrite
chokes to see if that might help).
Rick KN6KB
On
4/16/2019 9:27 AM, KE0GYC wrote:
For a small pack with limited current, Turnigy makes
a ready-built protected 2.2Ah pack for $25
Especially for newer builders, this might be easier than
a DIY pack with protection.
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You can use any CC/CV charger set to the appropriate voltage and current settings.
I use a lot of the cheap dc-dc buck modules.
For the Turnigy pack, set the voltage to a hair under 12.6 and the current to 0.5A and connect to a DC source of 13.8V and it should charge just fine.? You can connect it directly to the discharge port.
As for balancing, I just plug one of these into the mini balance/charging plug every few charges.? It will drain the highest capacity cell slowly to balance the pack.? It doesn't need to be done every charge, but should be done periodically to maintain cell balance.
These will work with most any lipo battery pack, homebuilt or otherwise, as long as you have the right wire connections.
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I also have a pack like the one KN6KB linked to, and it works great and is easier to use, but isn't really the best for building into a radio because of the power switch and unnecessary bulk, and you can't really cut out the power cable and replace with your own (like Power poles) unless you want to do a bit of surgery.
It works great as an external pack though!
For the Turning pack, I forgot to mention: you could always buy a ready-made balance charger if you want as well, but the buck converter and external balancer is more versatile for me.? It works great with solar panels, you can plug it into any wall wart of high enough voltage, or you could charge from your car battery on the go.
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On Tue, Apr 16, 2019 at 11:41 AM, Jerry Gaffke wrote:
Any recommendations on a suitable charger for this battery pack?
I've used a knock off of this knock off for years? ? --
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On Wed, Apr 17, 2019 at 09:38 AM, Doug W wrote:
I've used a knock off of this knock off for years?
Also worth mentioning, I charge and keep battery packs in an outbuilding away from anything flammable in a fire safe bag like this ? --
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?I have been looking at Drok's sight this morning.. love reading the reviews ?? found this?that looks like I can set to 12.x volts out and either plug in a 13.5v PS in the shack or a lipo or whatever battery.. on or off solar panel and it will give me 12.x volts all day..? ?I am no ex-spurt so if any of you see something I am missing I welcome the wisdom..? for a start I am thinking or one and then if it pans out that sending more power to the finals is a good thing I would consider a second one..? ?my (up purpased) case has room, I am planning seperate fast acting fuses for the raduino (1.5a) and main board (2a or 3a)... still sorting through the polarity protection options but I have power pole connectors for the power connection on the case..
73
KD9MDL
Bill
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Ted
Bill Lamm