Modulus

141 threads in the archive

Based on 141 threads · 32 cited

AI draft, not reviewedDraft, written by AI from the archive, every statement linked to its source — not yet reviewed.

The Modulus 3000 is tough hardware that ran for years, but repairs were slow and it was out of production by 2008 7 8. Don't count on it for HD: the Modulus 5000 HiDef Transmitter takes HD-SDI but converts it to NTSC or PAL analog output 1. Expect about 1 frame of delay from a transmitter and receiver pair, and know that range swings with your RF environment, with severe problems in Manhattan and on an aircraft carrier deck 27 5.

The questions 8

Is there a Modulus option for HD wireless video?8 threads · latest 2012

In short

Sort of: the Modulus 5000 HiDef Transmitter accepts HD-SDI, but it converts it to NTSC or PAL analog output 1. If you want HD all the way to the monitor, the sources point to the Boxx Meridian 2.

How the pros do it

Feed the Modulus 5000 HiDef with HD-SDI or composite video 1. It converts to NTSC or PAL analog output and supports both standards 1.
Pick 4:3 or 16:9 output, with letterbox or cropped formatting 1. The output is standard definition analog, so you use standard monitors with your existing modular receiving equipment 1.
Expect a bigger box than earlier Modulus units 1. Channel selection is push buttons now instead of the dual channel switches 1. Estimated price was about 2500 dollars 1.
Treat the 2009 test results with caution 1. Testing was on pre-production units with up-converted composite, and native HD-SDI into HD monitors had not been tested 1.
For uncompressed HD, look at the Boxx Meridian 2. It runs under 1 millisecond latency on the unlicensed 5.1-5.8 GHz band and has a built-in HD to SD downconverter in the receiver 2.

What changed

Earlier, in 2007, the Modulus 4000 transmitted on VHF and UHF channels 2 through 69 and switched between NTSC and PAL 3, today, as of 2009, the Modulus 5000 takes HD-SDI in but still outputs standard definition analog 1.

Ask a follow-up

How far can my Modulus transmit reliably?7 threads · latest 2009

In short

The sources give no distance figure for the Modulus, only that range depends heavily on the RF environment 4 5. A Modulus 3000 worked normally in Philadelphia and other cities with tall buildings, but had severe range and signal problems in Manhattan and on an aircraft carrier deck 5.

How the pros do it

Use a custom antenna cut to the operating frequency instead of the stock antenna 5. Operators reported better performance that way, though nobody tested stock against custom side by side 5.
In RF-heavy areas like midtown Manhattan, a better tuner with improved RF filtering helps keep the signal stable 5.
Don't count on switching channels to fix a bad spot, because it showed no meaningful improvement in the problem areas 5.
Keep the coax run as short as you can, because thin coax is highly lossy 6. Use thicker, better-shielded cable for longer runs 6.
Expect the Modulus to break up gradually as you reach its limit, while the IDX HD Transmitter stays clean until cutoff 4. The IDX range is roughly the distance a Modulus can travel before its signal degrades 4.

Ask a follow-up

Is the Modulus 3000 reliable on set compared to Canatrans?7 threads · latest 2008

In short

The Modulus 3000 hardware is tough and ran for years, but repairs were slow and it was out of production by 2008 7 8. Canatrans gets more consistent praise for reliability and support 8.

How the pros do it

Never change channels on a Modulus 3000 while it is powered on, because it can damage the electronics and slowly weaken the signal 9.
Carry a backup transmitter or line up a local rental, because a Modulus failed on a hot multi-week shoot with a repair estimate of at least two weeks 10.
Plan for parts trouble, because Modulus 3000 spares were hard to get as of 2008 8. Replacement rotary dials cost about 3.75 dollars from Digi-Key instead of 200 dollars through the manufacturer 9.
If you go Canatrans, budget for size and cost, because it is noticeably wider than the Modulus 3000 11 and was called expensive with size and weight concerns 10. Measured output was 0.42-0.65W at the 1W setting against 0.18-0.2W for the Modulus 3000 8.
Keep a high-channel Modulus away from your focus assist device, because it can transmit unintended signals beyond its selected channel and cause interference 12.

Caution

Changing channels on a Modulus 3000 while powered on can damage the electronics 9.

Opinions differ here

Operators disagree on Canatrans 11 8. Some praise its reliability and customer service 8 7. Others found it pricier without proportional picture gains 8, and some field users reported poor picture at 20 feet with high-gain yagis and dual units on adjacent channels 11. In one 2004 comparison at equal power the Modulus 3000 came within 15 percent of the Canatrans 2 9.

What changed

Earlier (2004-2005) operators called the Modulus 3000 a reliable workhorse with only slow repairs as the complaint 9 7, today (2008) it is out of production with spare parts hard to get 8.

Ask a follow-up

What frequency does my Modulus use, and is it legal?7 threads · latest 2007

In short

The sources don't state a Modulus band or frequency range 13. They do say the Modulus 3000 isn't legal for general US use without an FCC waiver 14.

How the pros do it

Check which model you have, because the Modulus 3000 puts out approximately 700 milliwatts 14.
In the US, the Modulus 3000 is not legal for general use without an FCC waiver, and the thread limits it to US Federal Agencies with that waiver 14.
Modulus units use synthesized channels rather than multiple dedicated chipsets, so you work by channel number 13.
Find an RF frequency chart that maps channel numbers to frequency ranges in megahertz 13.
Check that chart before you power up when other RF systems share the location 13.
Outside the US, check local rules first, because regulatory approval and the legality of frequencies differ between countries 15.

Caution

Don't run a high voltage battery pack into a receiver built for lower voltage input, because it can cause premature failure 16.

Ask a follow-up

How do I stop my Modulus interfering with my follow focus?6 threads · latest 2010

In short

Keep the Modulus away from the Bartech receiver and don't put it right against the BFD 17 18. Keep a Modulus 3000 below channel 50 18.

How the pros do it

Don't put the Modulus directly against the Bartech receiver, because that causes interference whatever channel you pick 18. Keep it away from the BFD too 17.
Set a Modulus 3000 below channel 50 18. Canatrans units only go up to channel 50 and don't show the same channel problem 18.
Keep the tape tubes above the mattebox 17.
Isolate the motor cables from your other cables, since they can act as antennas and carry RF into the receiver 19.
Low battery voltage can make the motor oscillate and look like interference 20. Test the receiver away from other RF gear, and a red light at close range means it needs servicing 17.
If the twitching persists, change the wireless channel, though it can come back at a different location 19. Ask the manufacturer about receiver software updates 19.

Opinions differ here

One account says keep the Modulus below channel 40 when running a BFD 20. Another says RF problems often clear up on Modulus channels 30 or higher 17. A third says keep a Modulus 3000 below channel 50 18. Some users also ran BFDs next to several wireless mics and transmitters with no trouble, and susceptibility varies between BFD units 20.

What changed

Earlier, in 2004, operators kept the Modulus below channel 40 alongside a BFD 20, while today, per 2007, the advice is below channel 50 for the Modulus 3000 18.

Ask a follow-up

Which antennas should I use on my Modulus?6 threads · latest 2009

In short

On the transmitter, run an antenna cut to your operating frequency 21 22. On the receiver, run a diversity setup that mixes directional and omni antennas 23.

How the pros do it

Put a whip or slim-line antenna cut to your exact frequency on the transmitter 22. It works best within about 5 MHz either side of the tuned frequency 21.
A single antenna stretched across roughly 225 MHz does worse than custom-tuned ones 21.
If you have a Modulus 2000 with old rubber ducks, replace them, because the rubber degrades over time 22. Original CIT antennas are available but are considered mediocre 22.
On the receive side, mix yagis with omnidirectionals instead of using one type everywhere 24 23. Spread them around the corners of the space instead of lining them up along one side 24.
Shark fins, rubber ducks, telescopic whips and rabbit ears all give similar practical results 23. Receiver antenna quality and sensitivity matter more than transmitter power 25.
For the aerial connections on a Modulus 3000, Mini-Circuits makes BNC attenuators 26.

Caution

A transmitter without a tuned antenna can damage itself because it can't dissipate its power 25. A badly matched antenna turns transmitter power into heat 21.

Opinions differ here

Operators split on polarization 23. One side says horizontal receive antennas can work in multipath-rich studios where signals bounce in from all directions 23. The other side says vertical orientation may perform better in controlled conditions 23.

Ask a follow-up

How much delay does a Modulus add to my video?5 threads · latest 2010

In short

A Modulus transmitter and receiver pair adds about 1 frame of delay 27. That comes from one user's report, so treat it as approximate 27.

How the pros do it

Count 1 frame for the Modulus transmitter and receiver combination 27.
Add the camera's own delay on top of that, because a Sony F900 puts about 5 frames on its SD output 27.
Match the Modulus transmitter to the video standard of your receiving system, PAL or NTSC, or it won't work properly 27.
Don't carry these numbers over to HD, because the F900 figure is for the SD output only 27.
If you have live dialogue on set, expect audio and video to drift apart, and plan on an audio delay device for headphones 28.

Ask a follow-up

Who can repair my Modulus, and what should I check buying used?5 threads · latest 2009

In short

Cramped Attic is the repair shop with a documented fast turnaround of about 1.5 to 2 weeks 29. Buying used, bench-test the unit on 12V with a video feed and check buttons, interference and antennas 30 31 29 22.

How the pros do it

Send it to Cramped Attic first, since they turned Modulus 3000 units around in about 1.5 to 2 weeks 29. Custom Interface in Maine also repairs, but turnaround ran a year or longer 29.
Bench-test a used unit by feeding 12V through one of its cables and a video signal from a camcorder 30. Watch the transmission on a television receiver 30.
Check the channel buttons, because the original mushroom-shaped post breaks easily and the part is no longer made 31. Cramped Attic's replacement module cost about $175 per button in 2007, and the witness mark rotates 90 degrees 31.
Look for video interference, because some Modulus 3000 units kept it through multiple repair attempts 29.
Check the antennas, since original rubber ducks degrade as the rubber deteriorates 22. Custom-cut antennas tuned to your frequency block are available 22.
Price it by condition: in 2005 an unverified used 3000 was around $500, and a verified one could reach $1000-$1200 30.

Caution

The Modulus 2000 gets hot enough to burn you if touched 32. It can also damage velcro fasteners 32.

Opinions differ here

One view is that running the unit continuously beats frequent thermal cycling, since repeated heating and cooling can damage components 32. The thread reached no consensus on whether continuous operation or power cycling is better for longevity 32.

Ask a follow-up

Sources 32

All 32 sources

What operators found

Still argued about

Often in the same threads

Follow Focus17, BFD12, Docking Bracket3, MDR3, Top Stage2, Dovetail Plate4, Base Plate3, Low Mode3, Master Series2, Artemis2

All threads

Ask about ModulusThe answer cites the archive