I have been away from the hobby for a few years, I want to get back into it but things have moved on and I’m not up to speed with what is available anymore.
I want to convert a bunch of locos to battery powered wireless DCC. I have an NCE Gwire Procab throttle and a box of Gwire receivers but no decoders to connect them to. Now that QSI Solutions don’t appear to be in the market anymore what other products can I look at which are compatible with my receivers?
Red
Hi Red, welcome back. Now is the time to decide to find some used QSI decoders or change to a new system. Greg E. has many QSI decoders and maybe he will provide some ideas for you. I thought the G-Wire only worked with QSI decoders and the NCE Power Cab. It communicates on 900 Mhz band. The newer systems from RailPro and REVO DCC communicate on the 2.4GHZ frequency with unlimited channels and no channel conflicts.
I am available off-line or through my web site should you want to discuss. www.rcsofne.com
Don
Just for the record, I have no more QSI decoders for sale. I purchased 2 large lots of them and basically sold them for my cost (and double checked and programmed each one).
You will find the QSI on the used market, so hang on to your receivers.
Airwire is 900 MHz, but the signal is pretty much pure DCC over the air. There are several other deadrail alternatives working on the same frequency, and the Tam Valley stuff and there is also a throttle as an alternative to the Airwire throttle and the GWire throttle.
Greg
p.s. I assume you have the NCE GWire throttle, not the wired only ProCab (look similar)
Is the output of the GWire receiver DCC, but at logic level? I’ve never played with one.
Yes Greg, I have the wireless throttle which QSI developed with NCE. Will it work with any of the CVP products?
Yes Red, it works on the original 8 channels. Will run AirWire and QSI decoders.
Eric, it’s pretty much DCC changed to unipolar signal… 0-5 volts at the input of the receiver… the transmitter / receiver is a simple modem, put in a digital stream at one end and the same digital stream comes out the other.
The only fly in the ointment is the DCC timing from the Airwire products is a bit off spec, can cause issues… also the protocol/commands to enter service mode are not the same as I understand.
Greg
Theoretical technical question…
If I recall, the output of the G-wire receiver wasn’t exactly easy to feed into non-QSI decoders. It could be done in certain cases, but it required tapping the output of the receiver into the decoder at points other than the track power inputs. Could you take that output and feed it into the DCC input of the Tam Valley Depot booster? Would the booster accept the unipolar signal and convert it to “proper” bi-polar through the normal “boosting” process?
Later,
K
Kevin Strong said:
Theoretical technical question…
If I recall, the output of the G-wire receiver wasn’t exactly easy to feed into non-QSI decoders. It could be done in certain cases, but it required tapping the output of the receiver into the decoder at points other than the track power inputs. Could you take that output and feed it into the DCC input of the Tam Valley Depot booster? Would the booster accept the unipolar signal and convert it to “proper” bi-polar through the normal “boosting” process?
Later,
K
Kevin
I have looked at the output of both QSI and Airwire. Both are pure DCC with the following exceptions. The bit timing is at 9600 which is slightly below the minimum for 1 bits. Most decoders have a 1 bit range that exceeds the spec so this is not a major problem in most cases.
The problem with the QSI output is that it is at a logic level and does not have the voltage swing required by the standard which is necessary for many decoders in the market.
Most decoders get their power from the DCC signal which is the main problem. Some decoders such as those manufactured by Lenz only require a logic level input at the track input so work fine with no special requremens for hooking up.
The last issue is that the QSI receivers require a 5 volt input which much be provided to power them.
Hope that helps.
Stan
If you have a logic level, single-ended DCC bitstream, you could just drive an H bridge to get the higher-voltage (and current) bipolar DCC output to drive a standard decoder. But that’s a bit of work to support an obsolete product.
I’d be happy to trade one of these for some constructive feedback. It’s an amplifier that takes a logic level signal and boosts it up to standard DCC levels.
It is a kit, but it’s a very simple circuit, takes maybe 15 minutes to solder up. I have tested QSI, TCS and Soundtraxx decoders with it but only with my own control system. It requires 5v/gnd and the logic level input, the power can be from any DC source, I use a 14.8v Lipo.
Eric Reuter said:
If you have a logic level, single-ended DCC bitstream, you could just drive an H bridge to get the higher-voltage (and current) bipolar DCC output to drive a standard decoder. But that’s a bit of work to support an obsolete product.
Yes, it’s that simple… that’s also why AirWire embraced this early on. QSI just made something compatible.
I have enough QSI to last my life now, and the sound is way better than basically anything out there. Also while the G scale decoder is out of production, the custom ASIC developed by QSI is alive and well in other scales.
But I digress on the QSI… the LINX radio modem was chosen to be simple, cheap, and transparent (to the DCC protocol)
Greg
Martin, what you have, combined with a “radio modem” looks perfect for creating a deadrail system from a normal DCC system.
Looks like an H bridge “ic” and a PIC processor.
What kind of amp rating, and what about output short circuit protection?
Greg
Where would I find decoders for sale and what would a reasonable price be?
Red, RLDHobbies.com and Reindeerpass,com are sources for TCS and Soundtraxx 4-5Amp decoders. QSI is very tough to find these days, I have one to my name. There are others but I have not used them, Greg and other folks here would know more about those. The TCS and Sountraxx sound pretty good to me and for just running trains and honking horns and stuff, they work well. More esoteric things I have not tried. These are motor/sound/light units, they do it all. Figure about $150 or so.
Greg, I don’t worry about short circuit as this is designed to be directly coupled to the DCC decoder, there should be no shorts as long as you wire it correctly (two wires is hard to mess up and it’s a cheap IC anyhow if you do blow it ha) Also, that’s just the amp, I have a modular system with interchangeable network boards that produces the logic level DCC. It’s driven by an Atmel Atmega328p at 16Mhz. As far as specs, 5 amps is on the data sheet but I have not instrumented it to take exact measurements like stall current and such.
I think I’ve posted this before, can’t remember, anyhow here is the complete install in a U25B if you want to take a look. Control board is on the left, Soundtraxx TSU 4400 in the middle, amp to the right. 2200mah 14.8v Lipo is in the fuel tank.
Stanley Ames said:
…The last issue is that the QSI receivers require a 5 volt input which much be provided to power them…
Ooh, yeah. Forgot about that. So much for that idea. Likely best (absent a source of compatible QSI decoders) for Red to sell off his existing G-wire receivers to those who have the QSI decoders and use the funds to buy a new receiver for other brands.
Don, is the Revolution system on the market yet? Last I checked with Reindeer Pass, it was not yet available.
Later,
K
Kevin, the Revolution DCC is now available. I have my arriving next week. JK told me he tested with Soundtraxx and Phoenix. It seems this version has been selling in the UK with good results.
Don
Kevin, the Revolution DCC is now available. I have my arriving next week. JK told me he tested with Soundtraxx and Phoenix. It seems this version has been selling in the UK with good results.
Don
Kevin
I have been using the Revolution DCC equipment since the end of March.
So far I like it a lot.
Tom
For small locos you can use the Zimo HO decoders as they are rated at 30 volts and are small. Current of the MX645 wired version is 1.2 amps and has 3 watt audio output plus has 2 servo outputs. I use these on all my single motor trains.
I’ve had feedback from NCE and CVP. Both advise of compatibility issues between the NCE GWire cab and CVP receivers. So I’m now in the market to sell one never used throttle and 6 QSI Gwire receivers!
I’m finding it difficult to select a new system, its a minefield of poorly explained info out there. It would be great if there was a uniform standard as in the smaller scales.