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Posted by jj604 | Nov 03, 2017 @ 05:43 AM | 2,007 Views
Lemon have been working for some time on upgrading their LM0041 DSMX® Compatible 7-Channel Full-Range Telemetry Rx and the first production samples have just arrived with the test pilots today (3 Nov 2017).

Here are my first impressions. Note that I have not done any performance or range testing. The results of performance testing from the testers will probably appear on the Lemon Telemetry thread fairly soon.

Follow progress here:

1) The LM0052 is identical physically to the LM0041 and functionally virtually identical except that it adds a barometer and lacks the PPM out function (despite what the label says - Lemon designed the label before deciding to remove PPM to improve the Telemetry performance). It can be distinguished by the black label and the DSMP protocol indication.

2) It is supplied either with or without a calibrated Pack Voltage/Current sensor (XT60 or T-Plug variants are available). The sensor connector is now a greatly improved flexible wire of the same kind that Orange and Spektrum use for their satellites. It also includes a single wire for pack voltage sensing if you do not have the V/I external sensor and another which contains an external temperature sensor and a wire that outputs RSSI as an analog voltage. Finally there is a bind plug and a piece of double sided tape for attaching the Rx.

3) The LM0052 receiver weighs 0.4g more than the LM0041. At 4.5g the case makes up almost half...Continue Reading
Posted by jj604 | Oct 08, 2016 @ 04:23 PM | 7,270 Views
A new Chinese company called iSDT has started producing chargers which are a bit different than the usual run-of-the-mill 4 button jobs. I bought one of their very compact 150W SC-608 chargers to keep in my LiPo box at the field as it is particularly neat and convenient.

You can charge up the 1300-1500mAh size packs off an older 6S 4000-5000 which is not up to high currents but perfectly OK to run the charger without any additional cables. I have got into the practice of taking just 3x Graphene packs to the field and fly one, charge one, have one ready to go, since they can be recharged without any stress at 5C (10C if you really want to).

I noticed that iSDT had produced a particularly neat parallel charge board to go with this charger, so I bought one to see how it compared with my usual Paraboards. Then Banggood sent me one to review as well.

The iSDT balance board is expensive compared to the cheap HobbyKing parallel charge boards but it is particularly well designed and neat if you have an SC-608. It is called the iSDT PC-4860. It is explicitly designed to work with XT60 connectors.

It comes in a tiny box exactly the same size as the charger with a well made XT60 power and 6S balance connector. The balance board actually does up to 8S if you want to use it with another charger and supply your own 8S connector lead.

Bottom line? I'm very impressed with this unit and despite the higher cost, I think it is worth it.

First thing you notice is that it...Continue Reading
Posted by jj604 | Apr 08, 2016 @ 07:45 AM | 9,357 Views
Big thanks to Jim from Banggood who sent me an Eachine Gemini 2100 battery charger for review.


This charger is also sold under the Venom brand with slightly different cosmetics.


See picture 2

I normally only review stuff I have bought but this was a potentially attractive charger and I was interested to see how good it was. Most of my charging is done with higher powered units with separate power supplies but an AC charger is handy for those occasions when you don’t want all the hassle and size of the larger unit. A while back, I bought a Hitec X1 (made by SkyRC) just for the convenience and use it a lot, particularly for smaller packs.

There are plenty of dual and even quad chargers around that can charge two or 4 totally different packs at one time, and there are plenty of AC chargers around that do a single pack but there are not many that combine AC input and dual charging and decent power. The obvious one that comes to mind is the Graupner Polaron AC/DC Sports 240W made by SJ Electronics. The Polaron is a very nicely thought out quality charger with a unique vertical form factor, excellent color touch screen and menu system and dual 120W chargers when used with a separate DC supply. It drops to a total of 120Watt on AC however with that power shared over the two channels. The most powerful dual AC/DC charger I have found is the Ultrapower...Continue Reading
Posted by jj604 | Jan 18, 2012 @ 01:28 AM | 8,281 Views
I started a thread here describing my measurements of LiPo cell IR on some common packs as the temperature varies from 50˚C down to around -20˚C.