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Discussion Starter · #1 ·
This question has probably been answered already but,

I have fitted a Homby R8249 chip to an elderly Hornby Britannia with tender drive mechanism.
Running perfectly before fitment, but now inoperable on my anologue (12v) track
Same installation into a new DCC ready Hornby A4 using the onboard socket same result
My Bachman Class 20 with DCC on board runs quite happily on my analogue track.
The question"Do DCC chips have to be in anyway programed to allow them to run in basic 12v DC mode?"

Can some one point me in the right direction with this


Armchairmodeller
 

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QUOTE (Thearmchairmodeller @ 14 Dec 2008, 20:00) <{POST_SNAPBACK}>This question has probably been answered already but,

I have fitted a Homby R8249 chip to an elderly Hornby Britannia with tender drive mechanism.
Running perfectly before fitment, but now inoperable on my anologue (12v) track
Same installation into a new DCC ready Hornby A4 using the onboard socket same result
My Bachman Class 20 with DCC on board runs quite happily on my analogue track.
The question"Do DCC chips have to be in anyway programed to allow them to run in basic 12v DC mode?"

Can some one point me in the right direction with this


Armchairmodeller
DCC chips sometimes have to have the value of CV29 changed, but my Hornby R8215 chips run on DC, an elderly Triang P6 controller in fact, out of the box with no problems. I don't have the R8249 so I can't tell you if you can change the value of CV29 or not, but I would expect them to run on DC without needing to change the value of CV29.

When you said same installation, do you mean that you took out the decoder out of the Britannia and then put it in the A4? If so, how did you do that as you would have had to remove the 8 pin plug to fit it to the Britannia? Does the A4 run on DCC OK? If not then you may have blown the chip as some of the older Hornby mechanisms consume too much power for the hornby chip.

Keith.
 

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Hello and welcome to the Forum

The older Locos (pre DCC socket) if hard wiring , the motor brushes must be isolated from the chassis and power pickup from the rail - Check with a multimeter

If this has not been done , the decoders are probably fried , If you had bought TCS decoders you would get a replacement under there goof proof warrantee

Hope this helps

Regards

Zmil
 

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Discussion Starter · #4 ·
Perhaps I should have enlarged on my previous original question.
To answer Keith, the decoder fitted in to the Brit was a brand new chip with just the plug cut off and remains hardwired in place within the tender.
The A4 has a brand new out of the package chip installed and care was taken to ensure the orange wire on the plug was positioned to No 1 on the socket. I had assumed that like Keith that installation of decoder chip would remain invisible to a DC locomotive operating on an analogue track (as does my Bachman Class 20). May be the chip does require to be set to a CV of 29. On thayt score I think I need to talk to Hornby

To follow on with Zmils line of thinking about isolating the motor yes this was checked with a multi meter. Continuity exists from the rail right through to red wire solder point on the chip.Equally continuity exist from the black wire solder point to the return rail.
There is continuity from the chip solder points via the grey and orange wires through the motor.
thanks for the comments guys , further thoughts and comments would be appreciated

Philip
 

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You'll be pleased to know that the NMRA standards were set so that if you do put the plug in the socket the wrong way round, nothing gets fried, all that happens is that the lights don't work.

You didn't say if the locos still work OK on DCC. Do they?

On the Brit, did you make sure that the ends of the unused wires were insulated so that they couldn't short on anything or with each other? On the A4, make sure that the prongs on the socket aren't touching on the chassis if the chassis's metal. There have been cases od shorts being caused by the plug itself if the pins are too long.

I'm pretty sure that Hornby chips are supposed to run on DC without any changes to CV 29, but you could contact Hornby customer service and see what they say. Nothing ventured, nothing gained

Keith.
 

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QUOTE (Thearmchairmodeller @ 15 Dec 2008, 05:00) <{POST_SNAPBACK}>This question has probably been answered already but,

I have fitted a Homby R8249 chip to an elderly Hornby Britannia with tender drive mechanism.
Running perfectly before fitment, but now inoperable on my anologue (12v) track
Same installation into a new DCC ready Hornby A4 using the onboard socket same result
My Bachman Class 20 with DCC on board runs quite happily on my analogue track.
The question"Do DCC chips have to be in anyway programed to allow them to run in basic 12v DC mode?"

Can some one point me in the right direction with this


Armchairmodeller

***Hornby actually only partly implements CV29. For any other brand, a setting of 6 in CV29 if you are using short address, 36 if you are using long will give you dunning on DC as well as DCC. Try these.

Alternately, read CV29 and see if it is odd or even. If it is odd, then make it even (ie, if 7 then make it 6 or 8, 37 then make it 36 or 38)

Every other brand available defaults DC running to "on".

Personally I would seriously consider changing to another decoder brand for future purchases - Sure they are cheap but you get exctremely limitied power handling and almost no adjustability at all as they are stripped of features to the bare bones.... you'll be far better off long term with Bachmann or TCS decoders for example.

Richard
 

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Ian Wigglesworth
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An extract from an email I received from Hornby DCC customer support, doesn'r really help for programming CV29 though, instructions sheet isn't that great either!

The R8249 supports the following CVs..

CV1.. Loco Address default is 3 Long/short addressing supported

CV3.. Acceleration default is 5 Range 0-255

CV4.. Deceleration default is 5 Range 0-255

CV7.. Version Number

CV8.. Manufacturer's ID = 48 (writing the value 8 to this CV resets decoder to default.)

CV17/18.. Used for setting up long address.

CV29.. the following bits are supported..

Bit0.. Default Direction.. default is 0 (normal)

Bit1.. Speed stepping default is 1 (128)

Bit2.. DC/DCC mode disable enable (power conversion)

Bit5.. Used re the Long/Short Address set up. (i.e. one or two byte address modes.)

Full interrogation in..

Direct, Paged, Register and Operate programming mode supported



I don't know what the default setting is though, like all other makes I would guess it would be set for running on both DC and DCC, but you never know!

You don't say what DCC controller you have, if you have the Hornby Select or the Bachmann EZ-command you wont be able to read or change any of the CV's anyway.

For more information the instruction sheet is here:-

http://static.hornby.com/files/r8249-1228e...leaflet-423.pdf

Hope this helps.

Cheers
 

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QUOTE You don't say what DCC controller you have, if you have the Hornby Select or the Bachmann EZ-command you wont be able to read or change any of the CV's anyway.
Not strictly true. The Select can alter CV1(address), CV3(acceleration), CV4(deceleration) and some CV29 values (Default direction, speed steps of the Select and analogue running enable/disable)
 

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Discussion Starter · #9 ·
Sorry if I appear slow to respond

I don't always get the chance to get back home as often as I would like.

To part answer Wiggy25 the intention was to slowly rechip my locomotives as funds were available BEFORE jumping in to buy a DCC controller (probably a Lenz) so my locomotives are being analogue controlled via an elderly (circa 1982) Gaugemaster controller

I am beginning to think that part of my answer lies in buying and stockpiling decoders until I can purchase a DCC controller and then convert all of my locomotives big bang style

Perhaps I am looking to convert on the cheap, and I should look to the more up market decoders from TCS or Lenz, although I had planned to buy British using the ZTC range of equipment until the company sunk on Sept 29th last

Latest I hear is SBX Models are about to build and distribute the ZTC product.... Any thoughts on ZTC decoders, I have read quality varies!

Thanks for your thoughts and comments.

Philip
 

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Personally I would avoid anything with ZTC on it. The consule itself is popular with the people who like to drive their trains although it does have it's quirks. High end price - if you are thinking of this sort of price & prefer a desk based unit then have a good look at the ESU ECoS or the Viessmann Commander.

As for decoders TCS are excellent & the Bachmann 3-function (which is a rebadged ESU) is excellent too - both reasonably priced too.

There is no reason why not to gradually convert the fleet & continue to use your analogue controller unless it is a feedback one.

Hope this helps.
 

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I would stay away from anything ZTC as while it looks good all it would be good for is a boat anchor. A Guagemaster (MRC) Prodigy, Lenz or NCE Power Cab would be the better choice. If money is not a factor then one of the ECOS units would be the go. As for the the Hornby decoders well I sent about a dozen back to Hornby with a nice note so they can recycle them back into their landfill. I'm hoping that I won't have to do the same when I get my sound equipped Duchess. Non sound decoders of choice would be TCS DP2-UK as these plug straight into the socket in most Hornby steam/diesel locos and some Bachmann locos. A TCS M1 covers those steam locos that the DP2-UK won't fit into. A TCS T-1 covers most of the diesels in both ranges. The T-1 is limited only by it's lighting functions of which there are two. If more lighting functions are required then a T-4, four functions or a T-6 with 6 functions covers most needs. This range of decoders will provide better control over a much wider range than the nasty stripped down Hornby or Bachmann decoders. Again if cost isn't a factor then Lenz Gold series decoders or Zimo decoders are the way to go. For sound in British locos then ESU Loksound decoders are the way to go. These decoders provide the operator with the ability to upload new sounds to the decoder, providing you have the required hardware to do it.
While it seems a good idea to buy decoders before purchasing a DCC system it's not as the DC control CV on most decoders may have to be turned on before the loco will operate on a DC system and to turn it on or off requires a DCC system.

Charles Emerson
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QUOTE (Ozzie21 @ 28 Dec 2008, 23:21) <{POST_SNAPBACK}>I'm hoping that I won't have to do the same when I get my sound equipped Duchess.

AFAIK Hornby are using ESU decoders for their sound equipped locomotives.

QUOTE (Ozzie21 @ 28 Dec 2008, 23:21) <{POST_SNAPBACK}>nasty stripped down Hornby or Bachmann decoders.

Not all the Bachmann decoders are "nasty stripped down" ones - the 3-function one is certainly an ESU albeit rebadged.
 

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Is your gaugemaster controller a feedback model? If it is then turn off the feedback as that can confuse chips.

ZTC 255 and 4007 decoders, the £12.95 ones do not work on DC unless it is "pure DC", (the quotes are David Nicholson's, former Director of ZTC), which I take to mean that the layout needs to be powered by smoothed DC or a car battery. I haven't tried that, and I don't know anyone who has. So unless SBX have reworked them so they do now run on conventional DC layouts you would be well advised to avoid them if you want to run chipped locos on DC until you can afford a DCC command station.

Also they don't seem to like certain Bachmann decoders and appear to run erratically when locos fitted with the Bachmann decoders are on the track at the same time, I speak from personal experience here with a Bachmann starter set loco. Others have reported runaways in similar circumstances. So sadly, as I too would like to support British jobs, I would not recommend them if they remain exactly as they were under the old ZTC regime.

Keith.
 
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