Britannia Builder

I've been caught out a few times by inadvertently leaving the brake (F27) applied after using it to stop the train. I have it set up as an on/off function in Railmaster. The train then refuses to respond to throttle movements, but all the sounds still work. Regards, John

On the first page of this thread I posted twice, on 1 and 3 April, to say that I'd twice in quick succession lost DCC control on one of my two 8TXS locos and had to reset with CV8=8 to recover. The strange thing is that this hasn't happened again in over a month of operation, and I can't think what if anything has changed. Perhaps I'm tempting fate! Regards, John

I use Railmaster with eLink to control 6 TTS locos and now 2 8-TXS locos. I only use the iPad to download the sound files and to set the CVs in real time, for which it is excellent. I can't imagine changing from Railmaster to the HM7000 app for train control in the foreseeable future - I really like the RM track display with point control, and the RM loco control is good enough. I might upgrade some but not all of my TTS locos to TXS in order to get better sound quality and better motor control and features such as F27 Brake and F28 AFC, which are both very good. Regards, John

Another way of varying the lowest speed to match the chuffs is to alter CV2, vstart. I've just changed this from 2 to 5 on my Bachmann 3MT Tank, and I get 4 chuffs per revolution which I think is correct for a 2 cylinder loco. The Railmaster scale speed parameters may have an effect on this too, so don't take the 5 as gospel. It's not as accurate as changing CVs 67 to 94, but much quicker if you just want realism at the slowest speed, and you can change CV2 in real time via the app. Regards, John

Hornby class 101 3-car DMU with 8TXS decoder, medium size speaker box and power bank, running the class 31 profile (and hoping for some sort of DMU profile in due course). Bachmann BR Standard 3MT Tank with 8TXS decoder and smallest speaker, both in the smokebox, and power bank in the cab, running the Black 5 profile. Both run very smoothly with excellent sound quality - motor control and sound quality both seem much better than TTS, of which I have 6 examples. Regards, John

This is interesting - it may well be the same problem that others including myself have reported as loss of DCC communication. I've had it 3 times on one of my 8-TXS decoders, but not at all on the other one. I've fixed it by setting CV8 to 8, but this is very inconvenient since it loses all my previous CV changes. If it happens again, I'll read the CVs from the app and see if the DCC address has changed, and if so I'll just reset that. It would be great to get to the bottom of this. Regards, John

Interestingly the photo on p120 of the decoder manual gives larger dimensions of 20x12.5x9.5 mm! I would measure it for you but both mine are now installed in locos. Perhaps someone else can measure one for you? Regards, John

I decided to check how long the power bank retains its charge when stationary on powered track. I've seen circuit diagrams of other stay-alives which have a high-value resistor across the capacitors to gradually drain them, so I was concerned that it might lose its charge after a few minutes in the station. So I ran the loco for 3 minutes to ensure the power bank was fully charged, then left it at rest on powered track with the sound on. I briefly flipped the track power off for a second or two every minute or so to check that the power bank kept the sound going. I'm pleased to report that the power bank was still going strong after half an hour, so it seems that if you can get across the first set of points after moving off at the start of a session, you should be good for the rest of the session! Regards, John

Thanks Rob, it's good to have that confirmed. If the charge-only-when-moving is a software rather than hardware feature of the decoder, perhaps in the future it could be changed to also charge when the sound is turned on? This would still allow the charging to be turned off when on the programming track, but would keep a sound decoder charged when at rest in the station. Regards, John

The other point to bear in mind is that the power bank does take a couple of minutes of running to charge up (according to the decoder manual). If the train sets off from rest at the start of a session and immediately hits duff points at the end of the platform, the power bank doesn't help. It's not clear for how long the supercapacitors retain their charge when the loco is sitting at rest on powered track, but hopefully some minutes. I can understand why they've chosen to only charge them when on the move, to preserve the programming track functionality, but in the new world of changing CVs from the app it's a mixed blessing. On the plus side, when the loco loses its DCC communication at speed and the only way of stopping it quickly is to cut the track power, the power bank doesn't send it crashing through the buffers! Regards, John

Hi Ray I've tried pressing the F28 test button once in the loco setup screen at the start of a session and that does indeed seem to send the 'sacrificial' F28 to the decoder that has no apparent effect, and thereafter the F28 on/off works at the first press and stays in sync with the decoder for the rest of the session. Regards, John

Just as a footnote to this, the relatively low voltage of the power bank does cause some speed hesitation when running over points with poor pickup. I believe that the power bank is less than 9V - it contains 3 supercapacitors each rated at I think 2.8V (from memory - the power bank is now tucked away in the loco's cab). It depends on the weight of the train - my Hornby 3-car DMU is relatively light and carries on without noticeable slowing down, but my Bachmann 3MT Tank with 3 coaches is heavier and slows down momentarily to a crawl before the 15V track power cuts in again. If I cut the track power, the 3MT comes to a halt within a foot or two, but its sound carries on for ages. I shall have to get the track rubber out and give my points a good clean! Regards, John

Yes, that's one of the attractions of F28 - I was able to remove F1 from the precious set of 6 buttons on the Railmaster small throttle display (I rarely use the large throttle pop-ups). Regards, John

Rob - surely Railmaster just sends the F28 message to the decoder without understanding what it means, and the decoder sorts out all the CVs etc? Paul - I think setting a macro to blank is how you delete it, although perhaps a simple Pause macro could be tried. I have an elink rather than elite. The HM DCC app works correctly with a single press of F28, but I'm aiming to operate everything from Railmaster. Ray - F1 does reliably turn the sound on with a single press, but I can't remember if F28 then works with one press. However I was trying to achieve a single press of a single button! I really only raised this issue to draw attention to what may possibly be a minor bug in the TXS decoder - I'm not too bothered about finding a workaround, but many thanks for the suggestions. In the meantime I'll keep pressing the button twice! Regards, John

I've just had this problem again - the loco was running at a fair speed under DCC control and suddenly lost communication. I had to start up the app on the iPad and switch back to Bluetooth in order to stop it, and then set CV8 to 8 to to get the DCC working again. I do have an emergency power-off switch for the track, but even so this is risking a collision. Having to reset all the CVs again afterwards is getting to be a big chore - auto calibration, AFC functions, sound volumes etc. I'm inclined to put the loco away (only one of my two 8TXS locos has been affected so far) until the problem is fixed by a firmware update. Regards, John

Thanks - I've tried shortening the button caption to 'AFC on/off', but it made no difference. There's no macro - in fact macros don't seem to be allowed on on/off buttons. Other on/off buttons such as F1 Sound and Coal Shoveling work correctly, and the F28 button is very consistently wrong - it takes two presses for each HM7000 loco on the first use at the start of a session, then works on each subsequent press. Not a major issue, but I suspect there's something wrong with the decoder's handling of F28 on DCC. Regards, John

I have fitted 8-TXS sound decoders to two of my locos, and I like to use the AFC function on F28 in order to turn the sound on and off and get automatic horn/whistle when moving off, brake noise when stopping, and random whistles etc while running. However, having set up a Railmaster button for F28 with the caption 'Sound AFC on/off' I find that I have to press the button twice in order to turn on the function and get the sound on; thereafter it responds to each button press, but then the green of the on button is always out of sync with the decoder. Any ideas why this might be? Regards, John

I had the same problem yesterday. I tried various things, but I think it was writing 8 to CV8 that fixed it. Regards, John

I think the 12v LED strips are wired with groups of 3 LEDs in series, so the minimum voltage to light them will be something in the region of 6-7 volts. Regards, John

I think Wayne is after all correct in his post #2 above to say that it may be a voltage difference between the 15v DCC track voltage and the voltage of the power bank. In fact the power bank appears to contain 3 supercapacitors, not the 4 that Wayne uses, so I think will only have a voltage of about 7-9 volts? This may well be enough to keep the motor going, but my carriage LED lighting has a resistor in series to reduce the voltage across the LEDs to keep the lighting fairly dim and reduce the power consumption. So the power bank probably does feed HF03, but its lower voltage causes the voltage across the LED strips to drop below the minimum needed to light them. Regards, John

Yes, the LED strips are wired to the blue and green pins on the decoder socket, with a suitable resistor - 3 LED strips in the 3 coaches, joined by fine wires between the coaches. It would seem rather strange if HF01/02 and HF03 behave differently with respect to the power bank. Anyway, it's no big deal. Just tried the auto calibration out of interest - the train shot off like a scalded cat, but luckily stayed on the rails! The result is perhaps slightly smoother, although there was nothing much wrong with it beforehand. Regards, John

How strange! I should have said HF03 rather than HF01 in my previous post - I've edited it accordingly. Regards, John

That's an interesting point that you make about the voltage of the power bank, Wayne, but I think that the power bank must be feeding into the decoder circuitry after the point at which the HFnn feeds are taken off - if I cut the track power, the carriage LEDs on HF03 go out completely while the motor and sound carry on for 10 seconds. The schematic in the manual suggests that the HFnn feeds come directly off the bridge rectifier. If so, it seems an entirely sensible design decision to reserve all the power bank power for the motor and sounds. It might be worth updating the manual to clarify this? Regards, John

I installed an 8-TXS decoder in my Hornby 3-car class 101 DMU last week, and found that it frequently stalled on points and then went through all its start-up sounds before moving off again. This wasn't a surprise because the DMU only has pickups on one of its bogies, and the carriage lights that I fitted used to flicker on points with the old non-sound decoder, although the motor carried on with no apparent interruption. I had the same problem with a TTS decoder on my Peppercorn A1, which I solved by fitting pickups to the tender wheels. Now with the TXS decoder I've been able to buy and fit a Power Bank, which solves the problem completely. The train will run for maybe 10 seconds with the track power switched off, and if the train is stopped the sounds will play on for ages. Interestingly the carriage lights, powered from output HF03 on the decoder, still flicker on the points - they are obviously not driven by the power bank capacitors, presumably to save all the power for the motor. Having the option of the plug-in power bank is a great step forward! Regards, John

I've been using F28 to turn on AFC, in order to get the horn sound when moving off and the brake sound when coming to rest. This works very nicely. I noticed that it was also making other sounds at random intervals, both when moving and at rest. This is a feature of AFC which can be turned on by setting bits in CVs 59-66, but according to the documentation these are off (zero) by default. On inspecting the CVs in the app's CV editor, I noticed that some sounds had been set when the profile was installed. This is probably a useful feature, but it would be helpful to update the documentation to say so. Incidentally I had to power the decoder down and restart it after zeroing the CVs in order to get the random sounds to stop. The CV editor in the app is really excellent - it shows the individual bit functions separately in the CVs, to save having to do binary to decimal conversion. Regards, John