# Monoprice DMX Cable wiring



## cvhstech (Jan 7, 2015)

Hello,

I apologize for the noobish question, but we purchased bulk 5 pin dmx cable from monoprice. The cable has 4 wires... what pins should i connect these 4 cables too, im assuming pins 1,2,3 are the same as a 3 pin dmx cable would be? But where would this 4th cable go? I have attached the link to the bulk cable below...

http://www.monoprice.com/Product?c_id=115&cp_id=11509&cs_id=1150902&p_id=601680&seq=1&format=2

the item number is 601680 on monoprice.com .
Thank you for your help!


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## derekleffew (Jan 7, 2015)

Monoprice doesn't say what color the interior wires are, but hopefully:

Pin-out:
1-- Ground ; shield (the braid)
2-- Data- ; black wire
3-- Data+ ; white wire
4-- Data2- ; green wire (might be blue instead)
5-- Data2+ ; red wire (might be orange)

Looking at solder side of female XLR-5:



OR, http://www.controlbooth.com/threads/dmx-wiring.12060/#post-127260 (the opposite). Most important is to make the same color go to the same pin# on each end, AND, in the future, OPEN BOTH ENDS of any cable you are repairing or trouble-shooting.


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## cvhstech (Jan 7, 2015)

Awesome thankyou so much!


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## n1ist (Jan 7, 2015)

Make sure one twisted pair connects to pins 2 and 3, and the other twisted pair to 4 and 5.

[ Corrected to fix an obvious brain fart...]

/mike


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## DavidNorth (Jan 7, 2015)

n1ist said:


> Make sure one twisted pair connects to pins 1 and 2, and the other twisted pair to 4 and 5.
> /mike


 
Um, actually it should be shield on 1, a twisted pair on 2 and 3 and the other twisted pair on 4 and 5.

David


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## derekleffew (Jan 7, 2015)

n1ist said:


> Make sure one twisted pair connects to pins 2 and 3, and the other twisted pair to 4 and 5. ...


 (I'll bring this up before @JD does; see here.) We've no guarantee that the cable in question actually consists of two twisted pairs, but rather is four wires all twisted together. Since it's unlikely that signal will ever be sent down wires 4&5 (unless we're using ET's IPS devices, or "unauthorised" universe-saver adapters), it really doesn't matter, does it?


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## CanYouHearMeNow (Jan 7, 2015)

derekleffew said:


> (I'll bring this up before @JD does.) We've no guarantee that the cable in question actually consists of two twisted pairs, but rather is four wires all twisted together. Since it's unlikely that signal will ever be sent down wires 4&5 (unless we're using ET's IPS devices, or "unauthorised" universe-saver adapters), it really doesn't matter, does it?




Even though there is no use on those pins for USITT DMX, Soldering 2 extra connections shouldn't be too difficult or take much extra time. If you have those connections, you could make an adapter that would allow you to use one DMX cable to carry 2 universes and then split off on the other end so you could use all 4 conductors.

If you are only using 3 pin XLR, then you can't solder the pins so it doesn't matter. But if you are using 5 pin, what does it hurt?


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## TuckerD (Jan 8, 2015)

ANSI spec says that the second cable pair (4+5) can be used for lots of stuff but does specifically prohibit the transport of a second universe with them.


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## CanYouHearMeNow (Jan 8, 2015)

TuckerD said:


> ANSI spec says that the second cable pair (4+5) can be used for lots of stuff but does specifically prohibit the transport of a second universe with them.



As a standard it can prohibit it, but if you built 2 custom adapters, the cable can physically support it.


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## TuckerD (Jan 8, 2015)

Well yeah. A conductor is a conductor. You could also use rusty air craft cable or barbed wire. Doesn't mean its a good idea. And when cat 5 cable is so cheap why not just build spec cables.

Edit: word choice


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## robartsd (Jan 8, 2015)

TuckerD said:


> Well yeah. A conductor is a conductor. You could also use rusty air craft cable or barbed wire. Doesn't mean its a good idea. And when cat 5 cable is so cheap why not just build spec cables.


Each break-in or break-out for two universes on one cable would require 3 connectors - plus the 2 connectors on the run for a total of 8 connectors vs. 4 connectors (two on each cable). So assuming that you're building your own cables and neglecting the extra labor of attaching more connectors the cost of the cable would have to be at least twice the cost of the connectors before it would pay off to make these non-standard break-in/break-out adaptors.


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## TuckerD (Jan 8, 2015)

robartsd said:


> Each break-in or break-out for two universes on one cable would require 3 connectors - plus the 2 connectors on the run for a total of 8 connectors vs. 4 connectors (two on each cable). So assuming that you're building your own cables and neglecting the extra labor of attaching more connectors the cost of the cable would have to be at least twice the cost of the connectors before it would pay off to make these non-standard break-in/break-out adaptors.


I'm not the one propossing such an idea. I am in fact against it. In the post you quote I say "cat 5 is so cheap just build spec cables".


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## robartsd (Jan 8, 2015)

TuckerD said:


> I'm not the one propossing such an idea. I am in fact against it. In the post you quote I say "cat 5 is so cheap just build spec cables".


Yes, I was elaborating your statement, not arguing against it. Sorry for any confussion.


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## epimetheus (Jan 8, 2015)

What does cat 5 cable being cheap have to do with building DMX cables to spec? I realize we're pretty far into the minutia here, but still...


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## n1ist (Jan 8, 2015)

I just built and used such breakouts on my last dance show. That let me use the second pair of an installed run of DMX (the primary pair ran the house dimmer) rather than having to pull my own cable from the stage to the booth. It was a big time savings when I only have two hours for loadin, setup, and focus... I have also used one to pull two audio lines over an installed DMX.

/mike


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## techieman33 (Jan 8, 2015)

TuckerD said:


> ANSI spec says that the second cable pair (4+5) can be used for lots of stuff but does specifically prohibit the transport of a second universe with them.



Using a Y to get 2 universes out of one connector was the norm on Avolites consoles for a while.


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## TuckerD (Jan 9, 2015)

That wouldn't shock me but that still doesn't mean doing so is in line with spec.


epimetheus said:


> What does cat 5 cable being cheap have to do with building DMX cables to spec? I realize we're pretty far into the minutia here, but still...



Cat 5 is recognized by the spec as cable that can be used for building dmx cables. It is also really cheap. The spec recommends doing so for permanent or semi permanent runs. My opinion on the matter is that its cheap so of you use it on a non permanent run and you lose the cable to wear and tear it's no bibig deal. If I was a touring show I wouldn't be using it because I wouldn't have time to replace it.

@n1ist interesting scenario. That's one of the arguments I have a hard time debating. When you're on the road or in another house you have to get the show on. I don't know enough about audio line levels to feel one way or the other about your final comment. I wouldn't make that choice because of my lack of knowledge.


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## CanYouHearMeNow (Jan 9, 2015)

Cat 5 has the same resistance as the RS485 spec for DMX correct? So as long as matching twisted pairs are used, you could use that cable to carry 4 universes on one Cat 5 cable? And since the twists matter more than the shielding (especially if it is alone in EMT conduit), then that would be possible.

Am I correct in all of this?

I am not saying that coming up with your own adapters and changes is in agreement with the standard, but rather that there are modifications that, if done correctly, could make things cheaper/more flexible/adaptable.


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## TuckerD (Jan 9, 2015)

One cat5 cable has 8 conductors as four twisted pairs. The data connection requires a ground which can be shared by multiple data connections. So one cat 5 cable could support 3 universes. ENTTEC has a product for this that they presented at USITT 2014 but I couldn't find it online.

Like you said though, not spec. Just a modification that could be a convenience if you can't manage to run more than one cable or a modern network like Net3/ACN.

I seem to have managed to high jack another thread into a standards talk. Sorry @cvhstech If this conversation is to continue it might be good to do it someplace else.


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## derekleffew (Jan 9, 2015)

CanYouHearMeNow said:


> Cat 5 has the same resistance as the RS485 spec for DMX correct? So as long as matching twisted pairs are used, you could use that cable to carry 4 universes on one Cat 5 cable? And since the twists matter more than the shielding (especially if it is alone in EMT conduit), then that would be possible.
> 
> Am I correct in all of this? ...


A well-respected manufacturer appears to agree with you:
from: http://www.tmb.com/products/82-sneak-snake :

> *DMX over CAT5e Snake System*
> *Carry multiple DMX512 universes over a single CAT5e cable!*
> 
> - Available in 2-, 3-, and 4-universe versions. All utilize the same ProPlex CAT5e cable.


FYI, it's impedance and capacitance that matter more than resistance.

Another well-respected manufacturer USED TO offer XLR5 break-in / break-out "Universe Saver" adaptors enabling two universes down one 5pin cable, but the item has disappeared from its website. Perhaps the DMX police got to them?

EDIT: Lex Products responded thusly:

> We hardly ever see anyone that needs this anymore. Demand dropped to less than one inquiry a year, therefore we removed it from the website and price list to free up space.
> 
> We do still have the drawings and we can still make it using the old PN# DMXUSS. Only a few of the sales reps here will still remember it, but trust me...it's a thing.
> 
> While the ANSI standard doesn't support it, as @CanYouHearMeNow said, the cable and connectors will physically support the splitting operation. We don't make cables that are against the NEC because someone can get injured (like the Male-Male Edison I was asked about the other day, then screamed at and asked why we don't build it). But DMX cables, we do frequently make adapters because people usually have developed their own protocols, or use for them, and there is no code or standard that has to be strictly adhered to, like the NEC is for power. We do therefore make this, as well as strange 6-pin to 5-pin XLR adapters, 3-pin to RJ45 with odd pinouts, and other weird ones.


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TuckerD said:


> ... I seem to have managed to high jack another thread into a standards talk. Sorry @cvhstech If this conversation is to continue it might be good to do it someplace else.


It's not you, it's me. Control Booth management doesn't mind too much veering off/hi-jacking (some of our best conversations started that way) provided:
The original question asked has been answered, and
Discussion remains somewhat relevant, however loosely.


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## RickR (Jan 9, 2015)

I've found a reason to use the 2nd universe trick. Old installed lines being used for expanded systems. It's far cheaper than pulling new wire. And if it doesn't work then pull new wire anyway!


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## TuckerD (Jan 10, 2015)

derekleffew said:


> A well-respected manufacturer appears to agree with you:
> from: http://www.tmb.com/products/82-sneak-snake :
> 
> FYI, it's impedance and capacitance that matter more than resistance.



Cool use of the sheild as the Common / Gnd.

As far as impedance / resistance there is a strong relationship between the two (in fact the both use the same unit of measurement, the ohm). The way it was explained to me was that the characteristic impedance of a data line is the resistance of the line if it was of infinite length (yay calculus). When you have a wave traveling in a medium and suddenly the the medium is interrupted (in our case by the end of the cable) there is a reflection. By adding the resistor between the two conductors you make the cable to have the same resistance as one of infinite length and the waves can never reflect off of the end of the run because "it doesn't end". Really, this is the subject matter of upper level EE classes at a 4 year uni. But that is the lame man's definition that was given to me. So I think the two are pretty interchangeable.



CanYouHearMeNow said:


> Cat 5 has the same resistance as the RS485 spec for DMX correct?



Not quite. Cat 5e characteristic impedance is 100 ohms and RS485 cable is 120. The DMX Spec (ANSI 120) says that you need to use a cable with characteristic impedance of 100 to 120 ohms.

@RickR Your comment doesn't make a lot of sense to me. It's my opinion that if it's reasonable to pull another cable (which is pretty much always in my mind) that you should pull another cable. In the case that you gave it seems like it would be reasonable to do so. The only time that I have a hard time debating that is when you run into a foreign house with your show and suddenly they don't have enough DMX with a quick load in, as was mentioned in this thread earlier.

Your right that it certainly seems easier to just build some Y's and call it good but to me if you don't have to cut corners you shouldn't. Especially since it was pointed out earlier that a pair of two Y's (which is what would be required) is 3 times the cost of one new cable because of the number of required connectors. And the cost of the cable is pretty small if not negligible. Here is a 1000' of cable that meets spec for $50. http://www.amazon.com/dp/B0092TG310/?tag=controlbooth-20

EDIT: I should add that I understand that people do what they have to, and that no matter what I say I can't change the fact that it is possible to add another universe to a typical 5 pin DMX cable.


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## Chris15 (Jan 10, 2015)

TuckerD said:


> Your right that it certainly seems easier to just build some Y's and call it good but to me if you don't have to cut corners you shouldn't. Especially since it was pointed out earlier that a pair of two Y's (which is what would be required) is 3 times the cost of one new cable because of the number of required connectors. And the cost of the cable is pretty small if not negligible. Here is a 1000' of cable that meets spec for $50. http://www.amazon.com/dp/B0092TG310/?tag=controlbooth-20



Umm, if you factor in the cost of labour to run an extra cable in an installed setting, then the Y adapters are probably going to range between somewhat cheaper and WAY cheaper...


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## TuckerD (Jan 11, 2015)

I'd like to explore that in a little bit more detail. I could be way off here because I don't have real industry experience, nor do I really know how staff wages vary by location / house size. So forgive and correct me if I turn out wrong. 

I looked up the employment statistics for set and exhibit designers and for sound engineering technicians on the Bureau if Labor Statistics website. Unfortunately I couldn't find any info on electricians for the stage specifically but I am going to guess it isn't very much difference. 

http://www.bls.gov/oes/current/oes271027.htm
http://www.bls.gov/oes/current/oes274014.htm

The rest of this analysis assumes a few things: 

The median salary / wage of the person doing the install is $50,000/yr or ~ $23.03 / hr. I choose this because it's a nice number which is a bit higher than the same figure for set / exhibit designers for performing arts companies given by the BLS. (Link 1) 
The cost of a 5 Pin Male XLR connector is $5.00 if you buy more than one at a time
The cost of a 5 Pin Female XLR connector is $6.80
Cat5e cable costs $0.05/ft from Amazon
If it takes you half an hour to build the two Y connectors the total cost is $49.42

$12.02 Labor
$27.20 Female 5 Pin XLR Connectors (4x)
$10.00 Male 5 Pin XLR Connectors (2x)
$00.20 4' of Cat5e (12" tails) 
If it takes you an hour to adding another cable run in an installed setting, as you mentioned, the cost is $43.33


$24.03 Labor
$6.80 Female 5 Pin XLR Connector
$5.00 Male 5 Pin XLR Connector
$7.50 150' of Cat5e.
So you are only a little bit off by these calculations and I wouldn't imagine that anyone will really make the decision over $6. But I would like to recalculate the cost of labor if you were in the first or third quartile of earners. 

If you were in the first quartile of earners making $16.35 an hour then the cost of the Y method is 45.56 and the cost of the new cable method is 35.65
If you were in the third quartile making 32.82 an hour then the cost of the first is 53.81 and the second is 52.82, making it still slightly (and IMO insignificantly) cheaper. 


So that's the cost of labor. At some theaters it's worth it. In Billings, MT I would choose the new cable run every time because there aren't very many people who would really know when the Y is appropriate and what it does. Also the cost of labor here is pretty low. I don't work for pay and the very small number of technicians who work full time (which I can count on one hand) either don't have the expertise to know anything about DMX or don't make enough money to make the labor savings worth it. 

Here is another major issue with the DMX Y. It's hard to know exactly which cable pairs are used for what on which manufactures. On some devices they are test ports for manufacturing, applying a signal to them may have unknown consequences. On other manufacturers they aren't connected, because why would they be. So you have to be careful about where you install the Y and know that it isn't a "plug into anywhere to make two universes" device. Or (the worse situation) it isn't a DMX break out that will let you to split a run in two directions. To the community theater or small church that's exactly what it would look like, and those are the kinds of people who I see typically asking these questions.


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## Chris15 (Jan 11, 2015)

Australia has one of the highest labour costs in the world 

The estimate for an hour to run a new cable seems low. You've got 10 mins to terminate it. But the moment you need to go into a ceiling, under a floor, or fish it through conduit through several rooms etc. it adds up quickly. Plus the fact you would normally use 2 people to pull cable...
And one would normally not use UTP Cat5e for an installed run unless inside metallic conduit - which is far from the norm here, so you're looking at STP at a higher cost.

Cat5e sounds like the wrong answer for making tails also - it's too thick to get 2 into a boot and too inflexible for my liking, but that's personal preference...


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## techieman33 (Jan 11, 2015)

TuckerD said:


> I'd like to explore that in a little bit more detail. I could be way off here because I don't have real industry experience, nor do I really know how staff wages vary by location / house size. So forgive and correct me if I turn out wrong.
> 
> I looked up the employment statistics for set and exhibit designers and for sound engineering technicians on the Bureau if Labor Statistics website. Unfortunately I couldn't find any info on electricians for the stage specifically but I am going to guess it isn't very much difference.
> 
> ...



That's way to simple of a breakdown. The time it takes to run a new data line isn't a sure thing. It could take one guy an hour, or it could take 5 guys 2 days to run new conduit, drilling new holes in walls and floors, removing, and reinstalling equipment that gets in the way, etc. It can get messy fast. That's why when you see threads of people asking about what to do in their new theater you see people telling them to run more cable and conduit then they think they will need. It's cheap to do when it's being built, but can become extremely expensive later down the road. You also wouldn't terminate it with the ends you linked to, you would use panel mount connectors that usually run more like $10 plus. No room in the current box at either end of the conduit? Going to have to drop another $20 a side for a box and cover to put that new data run in. Then maybe your AHJ is really strict and you have to pay an inspector to come in and inspect your work on top of all of that. A DMX Y cable to squeeze another universe out of an existing cable isn't a perfect solution, but it is another tool in the tool box that can be pulled out when your in a pinch. And as a theater technician you can never have enough of those IMO.


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## TuckerD (Jan 11, 2015)

Ah. I had considered international markets. And you are right that it varies by situation. A good tech can make decisions like that based on his / the crew's labor costs. And cat5 utp might not be the best choice.

I know every venue is different. The perspective I was attacking this from was from the venues I have seen and worked in. I have never encountered an environment where the best decision if this situation had presented it's self there would be to add a Y over another cable. But I'm not a tech by trade, I am a computer programmer. 

In the places I have worked with, adding another cable from the booth to the stage isn't as much of a problem as it would be in the spaces you mention. 

And obviously you would want different connectors if this was going to be in the wall permanently. In that case then you shouldn't be building Y's Just hide the whole thing and hide the fact that you have two universes 1 cable by adding another box with two panel mount connectors. 

This conversation gets really tricky when you start looking at very specific installations because the techs who work there know their venue best.


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## n1ist (Jan 11, 2015)

Other things can really add to the cost. The venue I do the dance recitals at is on the local historical registry, so we can't make any permanent changes without involving the town board. Another one has asbestos and lead paint, so cutting anything requires remediation; I finally had enough changes to do that I got approval and ran extra conduit. It cost $3000 for the asbestos removal and $400 for air quality testing, and that was for about 5 square feet. 

Sure, if I had the option, I would pull new cable. I'd also much rather split a 5-pin or run temporary cat 5 before trying to run DMX up an audio snake. Even wireless has its place.
/mike


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## derekleffew (Jan 11, 2015)

Another flaw in the ointment:

TuckerD said:


> ...
> $27.20 Female 5 Pin XLR Connectors (4x)
> $10.00 Male 5 Pin XLR Connectors (2x)...


The break-in has two M and one F (console end), 
the break-out has one M and two F (dimmer/ML end), 
for a total of three A5M and three A5F.

Also, please stop calling these things Y-cables. Y-adapters is marginally acceptable. XLR5 break-in/break-out is preferred.


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## TuckerD (Jan 11, 2015)

Oops. That slipped my mind. Thanks Derek


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## RickR (Jan 11, 2015)

You guys have expensive XLRs! Most of our suppliers sell Neutrik male or female, solder on, etc for $10USD-ish list! Online I see 5-8. Shipping is a pain but really, $27?

Anyway; in the few cases I've done this I considered pulling new wire, for maybe 15 seconds. Getting an electrician to show up is a minimum several hundred. 2-3 old Belden 9729 or similar in a conduit (ETC RFU + LINK + DMX) means pulling new wire is a full week project for 2. Remove old wire, pull new through several points, re-terminate, test, fix. In some places the conduit is full and the conduit is in poured concrete floors & walls.

Then there is the admin. It would cost several hundred for my time to get the estimates, convince the school district facilities folks, follow up with the district admin. Building permits!

Note that in this calculation the materials aren't even a significant percentage of the job. Well, you get the picture.

In some cases I went with replacing the wall jacks. That means actually doing work on the building but it's minimal enough. Frankly making the adapters is harder than it sounds. On one job I tried to make the obsolete RFU cable do the job. Its rated a for it and it should have worked, but it didn't, still don't know why.


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## TuckerD (Jan 11, 2015)

That was for four parts Rick. And like was determined. It depends on the situation, obviously in yours the cost is way higher to add a cable. At the venues I am most familiar with that wouldn't be they case. And in those situations, which I modeled, the cost difference is insignificant. 

I do have another question though. How relevant is this problem, how many of you are actually in situations where you are using DMX like this rather than ACN?


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## RickR (Jan 11, 2015)

Most of these jobs have been public high schools, all designed by the same consultant with extremely similar systems, architecture, problems... Other places get other solutions.

If there was any possibility of installing a network for under $5000 I would have gone that way. But the calls were for *A* DMX output on stage, making it a second universe was a bonus! One place got 2 outputs because it was easy.


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## Jay Ashworth (Jan 12, 2015)

To clarify one point: inductive reactance and capacitive reactance combine with DC resistance to create AC impedance.

Cabling also generally has an interconductor capacitance spec which is (usually) in pF/ft; best I remember, that doesn't interact *directly* with the characteristic impedance of a cable design, since a 100ohm cable is a 100ohm cable, no matter how long it is. But I might be wrong; my Technician exam was 3 decades ago.


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