Search results for query: *

Are there any published tables for random vibration levels for different aircraft and different zones (locations within the aircraft)? In particular I'm looking for data for military aircraft; DO-160 gives levels if you have no service data but MIL-STD-810F doesn't (see FIGURE 514.5C-8).

Hi, I have a problem printing a small Gannt chart. When I try to fit it onto a single page I get most of the schedule but I am missing some bars/milestones as the printed timescale does not cover the whole project (hence some of the milestones etc are "off" the right hand side of the page). I...

This question has been asked before but not answered. Has anyone got a cross reference for RTCA-DO-160 test methods compared to MIL-STD-810F, MIL-STD-461 and MIL-STD-704.

Thanks. We've had similar problems with differential RS422 receivers and we had to connect the internal 0V together between boxes as you said.

IRstuff - are you talking about differential RS422 receivers? What do you mean by "reference" ground from box to box.

When I said that the chassis is floating, I meant that it isn't connected electrically to any point. Yes when the chassis is fitted in the aircraft then it will usually be bolted to the airframe and that will ground it. It would also have an earth strap fitted which would electrically bond it...

(I thought I'd posted the following but it appears not so I'll try again) I've a question about grounding as follows. I have a data logger that uses an isolated DC power supply. Hence the power return on the input to the DC/DC converter is isolated from the 0V on the other side. There is a...

Thanks for the links. As it says pre-d is better but post-d is cheaper and easier - it's difficult to decide whether you need pre-d or wheher post will be sufficient.

No I can't find anything either......it seems to be a "secret"

Thanks. I already "knew" that pre-d was better than post-D - do you have any links or articles that would explain why? I don't know much about the application yet so I don't know if they are transmitting on different frequencies (I guess they are).

I don't fully understand the problem. You want to measure the tension in an armature (I can't picture this). Any resistive strain gauge will measure at well above 1000 Hz so I don't understand why anyone says that this is a problem. Your only problem is making sure that the sensor is placed in...

Can anyone help me to understand the differences between pre and post detection diversity combiners. I'll describe the application. I've a digital PCM signal that is being transmitted at S Band (say 2GHz). It is transmitted using left and right hand circular polarisation. The receiving...

Sorry to reply to my own post but I don't know how to edit the original one....... If a component is spinning at constant rpm then is the main concern that it is strong enough to withstand the G.......if it lasts a couple of minutes then will it tend to last indefinitely (the component is an...

How do I go about testing the following - is there a standard (Like Mil-STd-810F)? If a component is placed on the rotor of a helicopter blade then what vibration test level should be used. The unit will experience mainly a constant G which is dependent on rotational speed and radius from the...

Nevada is a bit far from the UK. There must be some fundamentals to the design and how to evaluate and refine it.

Is there a good book or article which describes how to design and test a good fixture for vibration testing (say for random vibration testing of small electronics products) Some ideas.... Simulate the mass of the test specimen and weight distribution if possible. Test the fixture with the...

A comment on what IRstuff said. Yes there's the contract and the spec and then there's what's said.... That's the way to loose customers in future. What's said by the sales team can also be part of the contract. Ok so you might be able to win this battle by holding up the contract but unless...

I think you have described something that happens far too often. I'm trying to address a similar problem here by getting the requirements documented - but the level of detail needs to be more than just listing deliverables. The deliverable must be worded in such a way as it's clear as to what...

I've used livelink and it's ok. The one drawback was that it is difficult to explore......you need to know the exact locations (unless of course you use search). It's also difficult to drag and drop documents into (although it can be done). I think you can use hyperlinks in Livelink but I never...

DO any of you use web based project document management systems......ones where remote users can log in and view documents? If so which ones would you recommend or if you don't want to name them then what features do you like? Alternatively have you use an Intranet based system. I'd like one...