[Halld-tracking-hw] Signal hook-up cables.

[Curtis A. Meyer]

Hi Fernando -

           I was going to discuss this later this morning (at the 
tracking meeting), but when we went
back to the vendors, the prices were substantially higher than we had 
expected. So high, that we
have backed off to en earlier design. This leads to a few final spec 
changes on the transition
board that I am going to try to get written down later today and then 
get to you.

       Curtis

On 4/27/11 9:21 AM, Fernando J. Barbosa wrote:
> Hi Curtis,
>
> Please send me the part number/specs for the terminator so we can 
> finish the transition PCB and submit it for fabrication.
>
> Thanks and best regards,
> Fernando
>
> Curtis A. Meyer wrote:
>> Hi Slava -
>>
>>     we saw a similar issue, but noted that two things fix this.
>>
>> 1)  With these connectors, we can shrink the width of the transition  
>> board
>>        which opens up some space between the boards. Our estimate is 
>> 0.2 inches
>>        off of each side.
>>
>> 2)  We planned to tilt the cables at 30 degrees, so they come of the 
>> transition
>>        board at a downward angle, and then don't collide and can 
>> start bending sooner.
>>        This also eliminates the possible collisions with the 
>> neighboring boards.
>>
>>                                 /###
>>                               /    /  ###
>>         =========/==/===  ###
>>                                                  ###
>>                            30 degrees          ###
>>                              -----------------------
>>
>>      Curtis & Gary
>>
>> On 4/20/11 2:20 PM, Vladislav Razmyslovich wrote:
>>> Hi Curtis,
>>>
>>> I have checked the possibility of soldering Signal hook-up cables to 
>>> the transition boards, and found some problems. At first, after an 
>>> attaching the terminator to the cable, we will get the rigid end 
>>> with length equal 1" or so.  Plus an additional length for bending 
>>> part of cable. Finally we will get 1.25"-1.30" length that can not 
>>> accommodate easily in a row of places - see attached files. 
>>> Unfortunately, we have a lot of places on a CDC HV boards layout 
>>> where the space between neighbour transition boards egual .31" - 
>>> .39" min. Based on that, I guess the soldering process will be  
>>> extremely hard, and  for some places will be impossible. Due these 
>>> problems the your's previous version looks more preferable. Or we 
>>> should search an another solution. Maybe my opinion is not fully 
>>> correct, but an additional checking this issue by you and your team 
>>> will be important.
>>>
>>> Thanks and best regards,
>>>
>>> Slava
>>>
>>> On 4/20/2011 10:06 AM, Curtis A. Meyer wrote:
>>>> That appears to be ok based on our initial tests. Also, being able to
>>>> come up from the
>>>> bottom of the board can help.
>>>>
>>>>      Curtis
>>>> On 4/20/11 10:00 AM, Fernando J. Barbosa wrote:
>>>>> Hi Curtis,
>>>>>
>>>>> Is there enough space to use these terminators, considering the bend
>>>>> radius?
>>>>>
>>>>> Best regards,
>>>>> Fernando
>>>>>
>>>>> Curtis A. Meyer wrote:
>>>>>> Hi Everyone -
>>>>>>
>>>>>>      I have attached a picture of the coax connector we want to 
>>>>>> use to
>>>>>> connect the
>>>>>> wires to the the transition board. While we do not have a rating 
>>>>>> from
>>>>>> the manufacturer,
>>>>>> we tested this to 7500V (the maximum of our local supply) without a
>>>>>> problem. In fact,
>>>>>> this was higher than the simple soldered connections.
>>>>>>
>>>>>>      We also believe that the use of these connectors will
>>>>>>
>>>>>> 1)  Reduce the time to manufacture the cables by quite a bit, thus
>>>>>> saving
>>>>>>       money there.
>>>>>>
>>>>>> 2) Reduce the time it takes to make the solder connections to the
>>>>>> transition
>>>>>>      board, thus saving money there.
>>>>>>
>>>>>> 3) Provide a more robust connection to the transition board that
>>>>>> could actually
>>>>>>      be unsoldered if we needed to.
>>>>>>
>>>>>> 4) Essentially protects most of the transition board region from
>>>>>> exposed high voltages
>>>>>>      and sharp edges.
>>>>>>
>>>>>> 5) Allows us to have the two soldered pins either go down through 
>>>>>> the
>>>>>> top of the
>>>>>>      transition board, or come up through the bottom. This will 
>>>>>> allow
>>>>>> us to make some
>>>>>>      wires shorter than they would need to be other wise.
>>>>>>
>>>>>>      The cost of these parts is about 13k$, but we think that the
>>>>>> above savings and benefits
>>>>>> will more than pay for this. Unless there are serious complaints, we
>>>>>> are going to order
>>>>>> ~3700 of these this week. There is a six-week delivery on them.
>>>>>>
>>>>>>         Curtis
>>>>>>
>>>>>>
>>>>>> ------------------------------------------------------------------------ 
>>>>>>
>>>>>>
>>>>>> ------------------------------------------------------------------------ 
>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> Halld-tracking-hw mailing list
>>>>>> Halld-tracking-hw at jlab.org
>>>>>> https://mailman.jlab.org/mailman/listinfo/halld-tracking-hw
>>
>>


-- 
Prof. Curtis A. Meyer		Department of Physics
Phone:	(412) 268-2745		Carnegie Mellon University
Fax:	(412) 681-0648		Pittsburgh PA 15213-3890
cmeyer at ernest.phys.cmu.edu	http://www.curtismeyer.com/