Maker Pro
Maker Pro

Door King 1830-01 POTS telephone hum prevents data send/receive.

fred3

May 10, 2023
4
Joined
May 10, 2023
Messages
4
We have a Door King 1830-01 which uses Plain Old Telephone system (POTS) communication for data in addition to telephone calls to residences from the controller. The telephone line is clean but, when connected to the 1830-01, there is a fairly strong 60Hz hum on the line.
The telephone company tested the phone line on site and found no troublel with it. We did the same today and confirmed that the line (at the connection to the 1830-01 is without the hum. But, when the 1830-01 goes "off hook", the hum is evident. So, we blame the main board - which is really the only board of significance.
Has anyone seen this? Does anyone know of a fix? We are capable of dealing with the electronics and the board in replacing components We just don't know where to start.

Thank you!!
 
Last edited:

Martaine2005

May 12, 2015
4,970
Joined
May 12, 2015
Messages
4,970
Sounds like a power supply issue or even dirty connections.
Filter caps would be my first suspicion, but I don’t know if the unit is line (tel) powered or mains powered.
Check the GROUND connections too, as often these deteriorate/oxidise on external metal/clad housings.

Martin
 

73's de Edd

Aug 21, 2015
3,658
Joined
Aug 21, 2015
Messages
3,658
Sir fred3 . . . . .

BEFORE
blowing an exploratory $80.00 + pig-in-a-poke ?
(Plus there is a CHEAPER alternative for that isolation transformer if . . .IF . . . IF even needed

PLUS initially troubleshoot . . .thusly . . . . .

CHECK YOUR UNIT FOR THESE COMPARATIVE ASPECTS . . . . .

Photo 1
RED ARROW
Item 1's of which, one may be the diamond shaped TO-3 encased 3 terminal regulator
and its like shaped heat sink. And this photo seems to suggest of a TO-220 shaped 3 terminal plastic 3 terminal regulator and its rectangular shaped companion heat sink .

RED ARROW item 2's blue cased AXIAL main electroltytic capacitor.

Examine the markings on all items . . . . . of particular interest will be a 7812 or 7815 on the far left regulator and possibly a 7805 on the right regulator.

The item 2 will have a capacitance and DC working voltage identification.
Also look at the right top corner for the 2 companion RADIAL leaded E-capacitors for their voltage rating and capacitances.

Move down to the Photo 4 and see the possible alternate use of a second TO-3 ( BOTH RED CIRCLED)and thus, the vacancy of the second previously pointed out plastic TO-220 at the top.

Look to bottom right corner and get that 3 terminal plastic TO-220 numbering and also the 4 o clock positioned RADIAL E- cap's voltage and capacitances..


MOVE TO PHOTO 2 . . . . .

See if they used / incorporated either phone line and or power line suppressors . . .within 10 ft of your unit.

The ferrite filter blocks shown down at the bottom mainly have to do with any STRONG nearby AM radio station coming in on the background.


GROUNDING
Look at my Photo 1 GREEN SQUARE of the unit ground wire to case and then to Photo 3 and its connection into terminal block #3.

MAKEE -MAKEE- TESTEE- TESTEE

Get your unit making its nasty noise and take the ground wire loose from board terminal 3.
Does the problem change ? then listen while you put it back into connection with terminal 3. . . . . . any change ?
If satisfied, of no problem, reconnect to #3 and tighten along with its other ends terminal and its screw, along with its biting in lock washer . . . . . . to be TIGHTENED.

Initially, take note or mark each of the incoming phone wires on terms 1 and 2 and then remove to see if the offending noise still is present ? ? ?

If so, we are then suspect of the 1830 board, so that is why the collecting of the data on the regulators and their related E caps .

Thaaaaaaaaaaaasssit . . . . . . . now talk some technicalese to me . . . . . babe . . . . .

MAGNIFICENT TECHNO PHOTOGRAPHIC REFERENCING . . . . .

DOORKING 1830 UNIT.png

(also Hosted) at
(Or the WHOLE fuchbuk is @

73's de Edd . . . . .


Conserve Toilet Paper ! . . . wipe with both sides of the sheet.


https://media.tenor.com/images/3ae0cf699fbaff26ad74d5755d0b8a63/tenor.gif
 

Attachments

  • 1683970393535.png
    1683970393535.png
    1.3 KB · Views: 8
Last edited:

fred3

May 10, 2023
4
Joined
May 10, 2023
Messages
4
Sir fred3 . . . . .

BEFORE
blowing an exploratory $80.00 + pig-in-a-poke ?
(Plus there is a CHEAPER alternative for that isolation transformer if . . .IF . . . IF even needed

PLUS initially troubleshoot . . .thusly . . . . .

CHECK YOUR UNIT FOR THESE COMPARATIVE ASPECTS . . . . .

Photo 1
RED ARROW
Item 1's of which, one may be the diamond shaped TO-3 encased 3 terminal regulator
and its like shaped heat sink. And this photo seems to suggest of a TO-220 shaped 3 terminal plastic 3 terminal regulator and its rectangular shaped companion heat sink .

RED ARROW item 2's blue cased AXIAL main electroltytic capacitor.

Examine the markings on all items . . . . . of particular interest will be a 7812 or 7815 on the far left regulator and possibly a 7805 on the right regulator.

The item 2 will have a capacitance and DC working voltage identification.
Also look at the right top corner for the 2 companion RADIAL leaded E-capacitors for their voltage rating and capacitances.

Move down to the Photo 4 and see the possible alternate use of a second TO-3 ( BOTH RED CIRCLED)and thus, the vacancy of the second previously pointed out plastic TO-220 at the top.

Look to bottom right corner and get that 3 terminal plastic TO-220 numbering and also the 4 o clock positioned RADIAL E- cap's voltage and capacitances..


MOVE TO PHOTO 2 . . . . .

See if they used / incorporated either phone line and or power line suppressors . . .within 10 ft of your unit.

The ferrite filter blocks shown down at the bottom mainly have to do with any STRONG nearby AM radio station coming in on the background.


GROUNDING
Look at my Photo 1 GREEN SQUARE of the unit ground wire to case and then to Photo 3 and its connection into terminal block #3.

MAKEE -MAKEE- TESTEE- TESTEE

Get your unit making its nasty noise and take the ground wire loose from board terminal 3.
Does the problem change ? then listen while you put it back into connection with terminal 3. . . . . . any change ?
If satisfied, of no problem, reconnect to #3 and tighten along with its other ends terminal and its screw, along with its biting in lock washer . . . . . . to be TIGHTENED.

Initially, take note or mark each of the incoming phone wires on terms 1 and 2 and then remove to see if the offending noise still is present ? ? ?

If so, we are then suspect of the 1830 board, so that is why the collecting of the data on the regulators and their related E caps .

Thaaaaaaaaaaaasssit . . . . . . . now talk some technicalese to me . . . . . babe . . . . .

MAGNIFICENT TECHNO PHOTOGRAPHIC REFERENCING . . . . .

View attachment 59025

(also Hosted) at
(Or the WHOLE fuchbuk is @

73's de Edd . . . . .


Conserve Toilet Paper ! . . . wipe with both sides of the sheet.


https://media.tenor.com/images/3ae0cf699fbaff26ad74d5755d0b8a63/tenor.gif

Thank you very much. For some reason, I didn't get an alert that there was a message here so I missed it until now.
Here is what I can tell you:
The system is powered by 18vac and I (so far) don't see any surge suppressors but haven't looked carefully yet. I guess they'd be in the bottom of the metal box.
We replaced the 1830-01 main board today and there was no improverment. So, I guess that eliminates a lot of things.
Haven't followed any of the suggestions yet as I just got this.
THANK YOU!!
 

fred3

May 10, 2023
4
Joined
May 10, 2023
Messages
4
We just tried disconnecting the terminal #3 ground wire. I tested it by calling into the gate and this time did not hear the hum. Yet, when I tried to transmit data, it continually failed as before.
Did I mention that this deteriorated over time. For a year it needed up to 3 or 4 tries to get a good SEND - so it was clear something was marginal. Eventually it just quit working - no surprise.
Now, of course, I'm wondering what to try next as there is a new main board.
 
Last edited by a moderator:

fred3

May 10, 2023
4
Joined
May 10, 2023
Messages
4
Show circuit drawing of existing system and how you connected the 1830
The system was installed by a gate company and had worked for years. The only power to the 1835 that I know of comes from one of the gates underground in the form of 18vac stepped down from 115vac/60Hz via an "isolation transformer" that I would just call a transformer. I don't imagine that the run length is of any real significance. This is connected to terminals #19 and #20 on the main terminal strip.
I measured voltage between each of those terminals and Ground and got somewhere around 8.5vac each - so it appears to not be inadvertently grounded on either leg.
The POTS telephone line is connected to terminals #1 and #2. The telephone techs say that the phone line is clean. I tested it with a handset calling out from those connection points and got no hum or noise. But, if I call in with a handset, after the connection is made, I hear what must be 60Hz hum - but not very high signal strength. I was a little surprised that what I heard would be enough to disrupt data communications - but it was the best clue I had. Note I reported separately that disconnecting the ground seemed to get rid of that hum but didn't fix data communications. Voice connections and telephone gate control both still work fine.
Clearly I'm still looking for suggestions.
 

Bluejets

Oct 5, 2014
7,097
Joined
Oct 5, 2014
Messages
7,097
I don't imagine that the run length is of any real significance.
It is in-so-far as wire size is concerned according to the spec supplied above.
Also it says max is 16 VAC, not 18.
Minimum 20VA

The system was installed by a gate company and had worked for years.
So what has changed, did the fault you mention just start on it's own or was there some other intervention?
Is there a battery backup system connected?
No visual indication of cap degradation near AC input filter?
 

73's de Edd

Aug 21, 2015
3,658
Joined
Aug 21, 2015
Messages
3,658
Sir fred3 . . . . .

Ol' Fred jes' sed . . . . .
We just tried disconnecting the terminal #3 ground wire. I tested it by calling into the gate and this time did not hear the hum. Yet, when I tried to transmit data, it continually failed as before.

Look at my photo 2 and then back to photo 1.
You can see that on photo 1, that terminal block 3 connects to a slotted wire connection terminal that connects to a short green wire length that passes the required distance to have another terminal lug at its end. That lug goes underneath a screw head, that is threaded into the whole metal case/housing of the whole unit.

Your findings in connecting to term 3 or not connecting to term 3 . . . . . . . along with its coincidental hummmmm-eee or NO hummmmm-eee
has thereby suggested a POOR / resistive grounding situation.

Now somewhere on that whole metal housing it needs to connect again to a wire route to a GOOD earth ground.
Can you find that second wire branch out ?, which will be connected into the metal case housing.


That true ground is usually being a cold water pipe clamp connection or a long 10 ft ground rod actually driven down into ye olde terra firma.

Time to now ask you if water plumbing in this specific immediate building is iron or copper pipe . . . . . or new gen plastic or PEX piping ?
A poor grounding could also relate to the "iffy" data transference.

Thaaaaaaaassit . . . .

73's de Edd . . . . . .

All pro athletes seem to be bilingual, they all seem to fluently speak, both, English and profanity.
 
Top