Author Topic: Installing a 1990's later polarity guard in WE 2702 BM...Need help  (Read 334 times)

Offline RotoTech99

  • **
  • Posts: 594
Dear Forum:

I have a WE 2702 BM that i'm wanting to put a 1990 later production polarity guard (see attached photo) into it, and I need some help and advice, please.

I have observed it wont fit under the 35AD4A dial due to the induction coils position, so I thought of putting it at the front edge of the phone where there's a gap between the 4010D network and the baseplate edge... I believe I could fit it on its edge after taping it to insulate it.

I know also i'd need to do something about the tab where it would normally go onto a WE 2500 dial bracket by taking a dremel tool and carefully trimming/ cutting off the bracket. Thankfully, the bracket with the "U" mounting boss has no circuitry on it, and is far enough from the circuitry to allow what i intend to do.

I'm looking for advice, and help with this, please.

Normally the Princess sets I deal with have the 4228 network, which is easier to place the plastic case enclosed one into because the internal gap between the base edge and network is big enough to accommodate it.

All advice and help welcomed.

Thank you, RotoTech99

Offline HarrySmith

  • ***
  • Posts: 5995
  • 1937 302
Re: Installing a 1990's later polarity guard in WE 2702 BM...Need help
« Reply #1 on: January 23, 2019, 06:23:42 PM »
Pictures of the insides of the phone you are working on might be helpful.
Harry Smith
ATCA 4434
TCI

"There is no try,
there is only
do or do not"

Offline RotoTech99

  • **
  • Posts: 594
Re: Installing a 1990's later polarity guard in WE 2702 BM...Need help
« Reply #2 on: January 23, 2019, 06:37:06 PM »
Dear Harry:

Can do,  the photos are attached below.

The Princess is a 2702 BM with a 4010D network.

Sorry if the photos are a bit rough,  I took them with my phone.

BTW: This is the same set I had the XTel retrofit dial in in another post.
Rototech99

Offline HarrySmith

  • ***
  • Posts: 5995
  • 1937 302
Re: Installing a 1990's later polarity guard in WE 2702 BM...Need help
« Reply #3 on: January 23, 2019, 07:45:37 PM »
OK. I think you have a couple of options. IIRC there is space under the dial where it should fit, I cannot tell from your pictures and I do not have one handy to look. Also it looks like you could remove the white clip from the top of the network that is holding the wiring and reroute the wires to make some space there. The last option would be to remove the ringer and use that space. Good luck, I hope it works out for you. Keep us posted.
Harry Smith
ATCA 4434
TCI

"There is no try,
there is only
do or do not"

Offline RotoTech99

  • **
  • Posts: 594
Re: Installing a 1990's later polarity guard in WE 2702 BM...Need help
« Reply #4 on: January 23, 2019, 08:15:44 PM »
Hello,

Thanks for the reply; I think it might fit under the dial.

I wouldn't remove the ringer,  but I think I could fit it where I suggested;

As to on top of the network,  I don't think it would fit with the housing on. I've attached another photo showing the area where I'd like to put it;

Its basically halfway between the right bottom corner of the dial, and the side of the network with the "C" terminal. Its basically the same spot where a polarity guard would go in a 4228 network equipped Princess.

I'm unable to lighten the picture,  but if you lighten it,  or use gamma correcting,  you can get a better look at the area.

I still believe I'd need to remove the mounting tab on the guard to improve its ability to fit in better; I just need to be sure it's cut off clean to minimize burring of the PC board material.
RotoTech99
« Last Edit: January 23, 2019, 08:27:49 PM by RotoTech99 »

Offline Key2871

  • **
  • Posts: 1601
Re: Installing a 1990's later polarity guard in WE 2702 BM...Need help
« Reply #5 on: January 23, 2019, 08:51:21 PM »
I had trouble with those in the past. They were actually attenuating the signal of either the network or the transmitter receive path of sets they were used in.
I had someone send me several sets that she wanted polarity guard's in. I put those in, then she complains that she either couldn't hear or be heard in conversation with those sets. I explained that she wanted me to use those, as she supplied them to me to install. I went with a small rectifier bridge is chip style, those worked everytime with no issues . And they are so small they fit in anywhere.
I even had sets with those in and had trouble at one point or another. Just my dimes worth ..

Ken
KEN

Offline RotoTech99

  • **
  • Posts: 594
Re: Installing a 1990's later polarity guard in WE 2702 BM...Need help
« Reply #6 on: January 23, 2019, 09:02:06 PM »
Hello,  Key2871:

I can understand that;  usually my big issue is finding where to place the guard in 2702B Princess sets... The 4010D are tricky to fit one in,  the 4228 net. equipped ones aren't as much as the guard tucks right between the net. and the base edge,  right next to where the net. and one side of the dial meet.

Most of my polarity guards come from 2500's that are otherwise scrapple,  or from some rotary sets where one was placed when end to end signalling was an issue.

RotoTech99

Offline Key2871

  • **
  • Posts: 1601
Re: Installing a 1990's later polarity guard in WE 2702 BM...Need help
« Reply #7 on: January 23, 2019, 09:37:33 PM »
Yup, I get that. I don't know what it is about some of those Western used, that some how failed a bit an caused problems. But when I used a bridge in my first set, and I never had a problem with them, I just stuck with them. I used four pigtails and tiny heat shrink on the legs of the bridge, they could ride around in there and hurt nothing.
Even the early ones, that came in a little plastic case, sometimes those would cause strange problems.
KEN

Offline RotoTech99

  • **
  • Posts: 594
Re: Installing a 1990's later polarity guard in WE 2702 BM...Need help
« Reply #8 on: January 23, 2019, 09:54:35 PM »
Dear Key2871:

I know what u mean..  My biggest aggravation is when the spring on the polarity guard board breaks,  or a wire comes loose you have to resolder.

A close 2nd is,  when the, snap down lid breaks, or doesn't latch... I can understand why they scotch tape it down,  and do the dial dust covers in a similar way.

I also wonder why WE chose not to put polarity guard circuitry in their 35 type dial design?  Seems like when they developed the 72 type with a polarity guard,  it was like smacking themselves on the forehead with their hand when they finally catch an obvious error they made.

Offline Key2871

  • **
  • Posts: 1601
Re: Installing a 1990's later polarity guard in WE 2702 BM...Need help
« Reply #9 on: January 23, 2019, 10:32:57 PM »
Those springs are actually fuse links. So if that breaks the phone won't work at all. I think it was some sort of lighting protection. I have found very small fuses in telephones with later dates. And if the phone doesn't work, I always by pass that fuse, and the phone works.
It's amazing how they meaning manufactures of electrical stuff have built in problems, in the form of fuses.
I have a carpet cleaner, not that old but just stopped working one day. I thought it was a switch, nope a well disguised fuse that was of the time delay type. One time went to turn it on and it opened and I thought I was going to have to replace a two year old cleaner. Now it still works great. Just something else to add to your knowledge of what to look for when something stops working.
KEN

Offline RotoTech99

  • **
  • Posts: 594
Re: Installing a 1990's later polarity guard in WE 2702 BM...Need help
« Reply #10 on: January 24, 2019, 06:54:46 AM »
Dear Key2871:

Thanks for the "411" (information)...  I am always amazed what I find unexpectedly,  and by what can fail when you least expect it to.

One of my rare success stories is taking the coil from a P-Type ringer,  and use it to replace a bad M-Type ringer coil assembly; the design is so close that they could be cross compatible.

Typically, only minor adjustment is needed in the airgap; the only tipoff to tell you the coil was a replacement would be on the opposite side of the coil,  the metal frame the coil mounts in may be smaller or with a series of holes, but nonetheless it fits into the ringer.

I did this with a NE M1 that had a bad coil,  and it worked.

RotoTech99