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Carriage PA system

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PFX

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One project I'm currently looking into at the railway I volunteer at is fitting a PA system to carriages. One carriage did have speakers installed but nothing further was done.

Is there anyone here who has knowledge on the technical specifications of PA systems used in carriage sets on heritage railways in the UK or beyond? Ideally a battery powered one would be required as our generator van doesn't run in summer months. It would also need to have inter carriage connectors that are easy to split and join to allow shunting and shuffling of stock and it would only be used with a microphone.

Any help would be greatly appreciated.
 
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SpacePhoenix

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Have you emailed any preserved railways? They might tell you how they went about adding a PA to their own carriages
 

Nym

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Not heratage kit but theres a few ways you can use chunks of consumer kit and a couple of twisted pairs to put together a UIC 568-esque system that would work nicely for PA only.

What is it you're trying to eventually acheive with this or is it truely a PA only system?

Depends on a lot of things even then,

Budget?

How often are carriages reformed?

Does it need to look heritage?

Does it need to be heritage?

What kind of signal quality are you after?

What will be driving it?

Is there already any through wiring?

Is the coaching stock electrically isolated?

What voltages are you looking to run at?

Does it need to include a talkback function?

Do you need cab to cab?

Does it need multiple handsets inputting into it?
 
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PFX

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Not heratage kit but theres a few ways you can use chunks of consumer kit and a couple of twisted pairs to put together a UIC 568-esque system that would work nicely for PA only.

What is it you're trying to eventually acheive with this or is it truely a PA only system?

Thanks for the response. I suppose it's easiest to answer in order.

Budget? - At present unknown though if approved, it will be low end.

How often are carriages reformed? - Not too often. More common that one carriage comes off the running set for maintenance.

Does it need to look heritage? - No.

Does it need to be heritage? - Again, no.

What kind of signal quality are you after? - Sufficient for a clear passenger announcement can be made.

What will be driving it? - Given I haven't a clue what to start with, I haven't a clue... Maybe that's just in general though.

Is there already any through wiring? - Currently only for lighting.

Is the coaching stock electrically isolated?

What voltages are you looking to run at? - Given the generator only runs in winter, it would need to be battery powered to enable summer use also, so I'd envisage 12v battery power.

Does it need to include a talkback function? - Not at all. It's purely for making announcements.

Do you need cab to cab? - No, our running consist is a steam loco, and between 2 and 3 carriages. The loco runs round at either end of the line. Hand held radios are used for guard to cab communication.

Does it need multiple handsets inputting into it? - No, all that's required is a single mic in the guard's compartment. Our coaches are non corridor stock and the guard would be the one using the PA.

Thanks again for the response.
 

dgl

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For a single Mic the best system would be what is known as a 50/100v line system driven from a master battery powered mixer/amp where the microphone is needed, separate volume controls can also be provided in each carriage if necessary. The amp would need to be powered from a car battery or similar.

Dependant on the volume required and how many speakers are wanted, if say there was 4 speakers per carriage then you would be looking at about 1-2w max per speaker (it might not sound a lot but for speech should be more than enough) and therefore for a 5 carriage consist you would need about 40W with some extra wriggle room although the actual power output is not too important so long as it's higher than the rating of all the speakers added together.

With 50/100v line systems the power output of each speaker is set on the speaker itself and therefore sets the max volume of each speaker (well how much roughly it is allowed to draw from the amplifier) and you can get inline variable attenuators (volume control) that would allow you to regulate the volume in each carriage.

As for equipment Thomann.de would be a place to start and this is where my suggestions of possible equipment will come from (this will be equipment that I have had no experience with so will literally be the lowest cost option but there is a 3 year warranty on all products). They are cheap and will ship anywhere.

For an amp one of their basic own brand swissonic unit would be the cheapest https://www.thomann.de/gb/swissonic_sa_65.htm it would give you 60W which with 4 speakers per carriage at 2w per speaker would allow for 7 carriages and can run on 24v. They also do a more powerful 120w version that has 12/24v powering ( hhttps://www.thomann.de/gb/swissonic_sa_125.htm )for a few (literally a few!) more quid. (€139/€149)

This would accept any standard microphone with the industry standard XLR connector. My suggestion being the Behringer XMS1800S, metal costruction and super cheap you ger 3 for about £30. https://www.thomann.de/gb/behringer_xm1800s_set.htm . and for cabling something like this, https://www.thomann.de/gb/pro_snake_tpm_6.htm , will be fine.
You could, of course, make you own mic panel if required/wanted and there are panel mount microphones and microphone switches available should you want to do that.

As for speakers something like this would be cheap if you don't want it built into the ceiling https://www.thomann.de/gb/thomann_wsp_135_6.htm , or for in ceiling mounting something like this would be a cheap option https://www.thomann.de/gb/rcf_pl_60.htm .

For connecting the carriages together you would need 2 wires to go between carriages and as this is 100V you would need connetors that are shielded for touch in both inlet and outlet. A suitable connector would be the weather resistant version of Neutrik's speakON connector with a rain/weather cover, this would allow the female end to be on the carriages and a short male-male cable for the connection between the carriages so it would not matter which way round a carriage is.
This, https://www.thomann.de/gb/neutrik_nlt_4_fp.htm , for mounting on the carriages and this https://www.thomann.de/gb/neutrik_nlt_4_fx.htm , for the cables.

The cable that connects this all together needent be anything special (although it might need to be fire rated), just 2 cores that can handle about 2A at 100v, 2 core orange lawn mower cable can usually be used without problems if the cable is ot stressed to much (although check the rules on whats allowed for 100V systems).
The internal speaker to speaker cable can be of the same type as the exterior cable if it makes it cheaper/easier.
Something like this, https://www.thomann.de/gb/the_sssnake_ssk_215_bk_100m.htm , would be perfect.

If it is decided that a wall mounted volume control would be useful then a variable attenuator such as this, https://www.thomann.de/gb/apart_e_vol_20.htm , can be used. This model can handle up to 20w.

Lastly a wall mounted speakON connector in each place where the amp may be situated (i.e. in every carriage where the guard may be located) will allow the amp to be moved as necessary and as it will be a parallel 100V system it does not matter where in the consist the amp is located.

Whilst I am not that knowledgeable/experienced with these systems this should give you a starting point. Websites such as soundonsound, and pro sound web should also be able to give you some advice.


And as for cost (excl. battery) for 5 carriages (20 speakers) incl. 1 amplifier, connectors (15 female (2 each on the outside and one in each carriage for connecting the amp) and 9 male (8 for the inter-carriage cables and one for he amp)) and 200m of cable, you would be looking at approx. £910 with wall/ceiling mounted speakers and approx. £890 with in ceiling (recessed) speakers.
 
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dgl

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Just an addendum to my previous post, I have edited it to provide some more information and more complete costings.

Sent from my Lumia 625 using Tapatalk
 

headshot119

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I've installed PA in MK1 coaches using "ripper" PA units taken out of ex BR MK2 stock.

Fairly simple and works off of the 24V lighting batteries, and uses the RCH jumper cable to transmit the signal between the coaches.

Might be a place for you to start looking.
 

PFX

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Just an addendum to my previous post, I have edited it to provide some more information and more complete costings.

Sent from my Lumia 625 using Tapatalk

Very much appreciated. Thanks for the info. I've used Thomann before for musical gear and they're very good.
--- old post above --- --- new post below ---
I've installed PA in MK1 coaches using "ripper" PA units taken out of ex BR MK2 stock.

Might be a place for you to start looking.

That's a possibility I hadn't thought of. There's a small amount of redundant stock around which may provide useful.
 
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tellytype

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Used to be around your part of the world. Now over the water running a broadcast engineering company.

Solutions will depend on budget. A 'hack it up from parts' solution if you have the skills will work.

Alternatively if there's a budget then PM me & I'm sure something plug n play can be designed but those solutions don't come cheap
 

PFX

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Cheers for the offer though in this case, the budget will be minimal. I think I may have speakers recovered from an old 450 class so if it goes ahead, it's going to be a Frankenstien's monster affair.
 

dgl

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As an addendum to my idea it's all standard shop/warehouse PA equipment so maybe look at places that are upgrading as you may be able to get some perfectly serviceable equipment for little cash due to the lack of any real resale value, although you may need to get an inverter as I would guess that most shop PA's don't have the option of 12V power.
 

JohnB57

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Isn't the most obvious solution a car based 12 volt mixer/power amp system? These are available very cheaply on Ebay and even if you used one PA per carriage, the whole amplifier system would be less than £125 or so. If you can scrounge some old speakers, you should be able to do this on a very tight budget. Don't forget, you're not looking for hi-fi - in fact, you need middle and top and as little bass as you can manage so it's all pretty low-fi.
 

LowLevel

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Do ask yourself though - 'is it really necessary?' and 'will installing non heritage equipment spoil the look of the carriages?'.

The very vast majority of preserved lines I've travelled on have no PA system and manage perfectly well - having guards and station staff bellowing away is part of the heritage charm - very few trains before the 1970s/80s had a PA system and it's something that's easy to get wrong.
 

PFX

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Thanks for further suggestions. All more food for thought. I've managed to locate salvaged speakers from an NIR 450 class unit. More than I'll ever need.

As to necessity, as our carriages are non-corridor (although they have connectors, they don't match up) and it would be very useful to announce delays and pass on information without having to stop the train, the guard then climbing down to the track and going from carriage to carriage. This would be particularly useful on our busy Halloween, Christmas and St Patrick's Day trains which tend to have very high loadings.

As to appearance, it's something I'd certainly be taking care to ensure doesn't detract from our stock.
 

sciisfun

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perhaps utilise an FM system, systems designed to transmit for cars would work well over a short range, if you get one that uses a line in a normal 3.5mm microphone would work
http://www.ebay.co.uk/itm/Bluetooth-wireless-LCD-car-mp3-player-fm-transmitter-Remote-SD-USB-Charger-Kit-/391183930751?hash=item5b1461157f:g:mfIAAOSw-itXt1DK
then standard fm receivers in the carriages via a amp, all powered via a 12V bus. allows for easy interchangeability, and minimal modifications, an external aerial in a shroud on the top of a carriage wouldn't even be visible!
 

Nym

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What's the spec on the NIR450 unit speakers?

A line level system with isolated return enable relay signals might be the best way to make use of them, combined with some off the shelf car amps car by car.

Only question mark would be the inter-car jumpers, but something as simple as a hard wearing XLR connector would do the business. I don't think you'd need to go for something like Harting 3As, unless you want super-reliable.
 

dgl

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Or if they have a transformer attached then a line system at the correct voltage would work.
Otherwise some sort of 12V/24V amp per carriage would work, however, you should not daisy chain line-level signals and each amp input should be buffered off the audio line (either using a passive (lossy) system or an active (powered and therefore lossless) system).
You would also need some sort of mixer/pre-amp to convert the mic signal to the line level signal required by the amplifiers (the little USB powered Behringer unit would do) and you would have to take care in wiring the speakers so that they have the correct total impedance for the amplifiers, too higher impedance and the amps will not be working very efficiently and too higher an impedance and you will damage the amp.

i.e. 4 x 8Ω speakers wired in parallel will give you 2Ω and in series gives you 32Ω.

As for standard line-level waterproof connectors these are waterproof XLR's
https://www.thomann.de/gb/neutrik_nc_3_mpr_hd.htm
https://www.thomann.de/gb/neutrik_nc_3_fxx_hd_d.htm
 
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