[Amps] B&W 850A Repair

[bill wylde]

Guyz,

I measured the diameter of two 850 coils and came up with a
nominal figure of .125".  Mind you, these measurements were
taken with very poor equipment.

I forwarded photos to Gary of one 850 that I rebuilt years ago.
The supporting arms of the small diameter (wire) coil were two-piece.
A flat 1/4" thick piece about 1/2" in width, and a small 1/4" width
piece that fit into a slot cut in the wider piece.  All this is said while 
realizing
that these were probably early models.  Later models, as I recall, used 
melted
rod to hold the whole mess together.

The 1/4" width pieces were initially notched on a table saw, and the
work piece was quite large.  Later the large piece was cut in small strips.
Worked very well for me.

If anyone would like to see the parts, please advise and I will send photos.

Bill Wylde, K9WXR

-----Original Message----- 
From: Carl
Sent: Saturday, October 27, 2012 8:29 AM
To: Paul Kraemer ; amps at contesting.com
Subject: Re: [Amps] B&W 850A Repair

Silver prices went up, plating thickness went down (-;

And #8 wire has long been a standard at .1285. Maybe your NIST boys are
using Chinese instruments.......

Thats my story and Im sticking to it.

Carl
KM1H


----- Original Message ----- 
From: "Paul Kraemer" <elespe at lisco.com>
To: "Carl" <km1h at jeremy.mv.com>; <amps at contesting.com>
Sent: Friday, October 26, 2012 8:57 PM
Subject: Re: [Amps] B&W 850A Repair


> And I measure it at 0.1245" to 0.1255"
> Our calipers are maintained by a lab using NIST standards and they were 
> recently certified
> Customer requirement---they pay for it---we enjoy the benefits
> Potato potahto, call it an 1/8" down here in the stix
> Paul K0UYA
> ----- Original Message ----- 
> From: "Carl" <km1h at jeremy.mv.com>
> To: "Paul Kraemer" <elespe at lisco.com>; <amps at contesting.com>
> Sent: Friday, October 26, 2012 7:04 PM
> Subject: Re: [Amps] B&W 850A Repair
>
>
>>I measure the wire at .1325 which equates to  #8 wire with the plating.
>>
>> Carl
>> KM1H
>>
>>
>> ----- Original Message ----- 
>> From: "Paul Kraemer" <elespe at lisco.com>
>> To: "Gary H. Harmon, Jr." <gharmon at idworld.net>; <amps at contesting.com>
>> Sent: Friday, October 26, 2012 6:57 PM
>> Subject: Re: [Amps] B&W 850A Repair
>>
>>
>>> Gary
>>> No support except the back end.
>>> Scaling "up" from a complete 851 (500w) the bars on the 851 are 5/16" 
>>> wide with 1/8" material below the coil
>>> Total thickness is the 1/8" plus wire diameter plus another 1/16".
>>> The top is melted to anchor the turns
>>> For the 850A that suggests that the bars need to be 3/8" wide by at 
>>> least 1/8" below the wire + the wire + another 1/6" (or more ) above the 
>>> turns.
>>> I would suggest a minimum of 3/8" square bars---or even up to 1/2" 
>>> square since the wire diameter is a hefty 1/8"
>>> Get some 3/8" or 1/2" stock from McMaster Carr and start notching with a 
>>> fine tooth band saw or jig (scroll) saw.
>>> The notch spacing is linear over the approximate 3 1/4" length of the 
>>> coil
>>> McMasterCarr doesn't list Lexan but this is similar 
>>> http://www.mcmaster.com/#polycarbonate-sheets/=jw6q79
>>> If you can find actual Lexan it is best. Does not shatter or chip. 
>>> Extremely strong and easy to work. It is used in bulletproof glass 
>>> windows.
>>> Have fun cutting all those notches! Clamp the bars together and do 4 at 
>>> once.
>>> Paul K0UYA
>>> ----- Original Message ----- 
>>> From: "Gary H. Harmon, Jr." <gharmon at idworld.net>
>>> To: <amps at contesting.com>
>>> Sent: Friday, October 26, 2012 3:07 PM
>>> Subject: [Amps] B&W 850A Repair
>>>
>>>
>>>>I need to replace the 4 plastic coil supports on my 850A band switching 
>>>>coil
>>>> assembly.  I have no pieces to measure so I need to know the width,
>>>> thickness and length of the four pieces.  Is there some sort of support 
>>>> of
>>>> the four pieces at the ends inside the coil or is the only fastener 
>>>> where
>>>> they bolt to the L-shaped brackets connected to the front of the 
>>>> assembly?
>>>> Any suggestions on how to fasten the coils turns to the strips?
>>>>
>>>>
>>>>
>>>> Vr,
>>>>
>>>>
>>>>
>>>> Gary H. Harmon, Jr. - K5JWK
>>>>
>>>> 6003 Archwood
>>>>
>>>> San Antonio, TX 78239-1504
>>>>
>>>> 210.657.1549h / 210.884.6926c
>>>>
>>>>
>>>>
>>>> "Retirement means every day is a Saturday except Sunday".
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> _______________________________________________
>>>> Amps mailing list
>>>> Amps at contesting.com
>>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
>>> _______________________________________________
>>> Amps mailing list
>>> Amps at contesting.com
>>> http://lists.contesting.com/mailman/listinfo/amps
>>>
>>>
>>> -----
>>> No virus found in this message.
>>> Checked by AVG - www.avg.com
>>> Version: 10.0.1427 / Virus Database: 2441/5355 - Release Date: 10/26/12
>>>
>>
>
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 10.0.1427 / Virus Database: 2441/5357 - Release Date: 10/27/12
>

_______________________________________________
Amps mailing list
Amps at contesting.com
http://lists.contesting.com/mailman/listinfo/amps