20th Apr 2020, 12:45 pm | #161 | |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
|
Re: Kolster Brandes 666 Valve radio restoration.
Quote:
Lawrence. |
|
20th Apr 2020, 12:45 pm | #162 |
Pentode
Join Date: Nov 2019
Location: Tewkesbury, Gloucestershire, UK.
Posts: 173
|
Re: Kolster Brandes 666 Valve radio restoration.
The heater pins for V1, V2, V3 & V6 are pins 3 & 4
o.k will continue to test except for heater pins 3&4 |
20th Apr 2020, 1:14 pm | #163 |
Pentode
Join Date: Nov 2019
Location: Tewkesbury, Gloucestershire, UK.
Posts: 173
|
Re: Kolster Brandes 666 Valve radio restoration.
Tested V3 Acquired following results :-
Pin 2 Volt meter set at 2V Reading of -.013V Pin 5 Volt meter set at 2V Reading of 0.344V Pin 1 Reading of 36V pins 3/4 heater pins not testeed Cap pin of valve Reading of 77V |
20th Apr 2020, 1:25 pm | #164 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
|
Re: Kolster Brandes 666 Valve radio restoration.
Pin 1. Screen grid. 36 VDC. Low.
Pin 2. Control grid. -0.013 VDC. OK. Pin 5. Cathode. 0.344 VDC. Low. Top cap. Anode. 77 VDC. Low. Anode voltage is well down. Could be down to leakage in C18. Screen grid volatge is well down. Could be down to leakage in C12.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
20th Apr 2020, 1:51 pm | #165 |
Pentode
Join Date: Nov 2019
Location: Tewkesbury, Gloucestershire, UK.
Posts: 173
|
Re: Kolster Brandes 666 Valve radio restoration.
Tested V2 acquired following results :-
Pin 2 Volt meter set at 2V Reading the reading found to be flucturating a little between reading values of .050V to .070V Pin 5 Volt meter set at 2V Reading of 0.52V Pin 1 reading of 27V Pins 3/4 not tested Valve Tube Cap acquired a reading of 73V |
20th Apr 2020, 1:57 pm | #166 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
|
Re: Kolster Brandes 666 Valve radio restoration.
Low anode voltage again. Could also be down to C18 being leaky. I reckon you'll find the same with V1.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
20th Apr 2020, 2:17 pm | #167 |
Pentode
Join Date: Nov 2019
Location: Tewkesbury, Gloucestershire, UK.
Posts: 173
|
Re: Kolster Brandes 666 Valve radio restoration.
V1 tested acquired following results :-
Pin 2 Volt meter set at 2V acquired reading of 0.48V Pin 5 Volt meter set at 2V acquired reading of .070V Pin 3 acquired reading of 21V Pins 4/5 not tested Cap pin of valve Reading of 74V |
20th Apr 2020, 2:20 pm | #168 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
|
Re: Kolster Brandes 666 Valve radio restoration.
Same again. Low anode and screen voltages. Should improve once capacitors have been changed.
Test the resistors next.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
20th Apr 2020, 2:25 pm | #169 |
Pentode
Join Date: Nov 2019
Location: Tewkesbury, Gloucestershire, UK.
Posts: 173
|
Re: Kolster Brandes 666 Valve radio restoration.
O.K ,
Will turn set upside down and go through and make note 0f all values of |
20th Apr 2020, 2:42 pm | #170 |
Pentode
Join Date: Nov 2019
Location: Tewkesbury, Gloucestershire, UK.
Posts: 173
|
Re: Kolster Brandes 666 Valve radio restoration.
Just had at look at C18 , solder joint dont look to briliant as quite old (wondering possible dry solder joint could cause low readings )
Have attached picture of |
20th Apr 2020, 2:56 pm | #171 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
|
Re: Kolster Brandes 666 Valve radio restoration.
No. A poor solder joint won't cause a capacitor to become electrically leaky.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
20th Apr 2020, 4:04 pm | #172 |
Pentode
Join Date: Nov 2019
Location: Tewkesbury, Gloucestershire, UK.
Posts: 173
|
Re: Kolster Brandes 666 Valve radio restoration.
Been checking the resistances done along the one side , my vault meter must have different hms settings as need to multiply the results to correspond with data of W/S service manual
Result Along 1 side of chasis (some differ a bit) R1 is definatly low 49,000 LOW (appears may be cracked halfway along) R2 67,000 (bit low) R3 75,000 R4 268,000 R5 262,000 R6 110,00O R7 110,000 (Appears also quite low) R8 10,000 R9 29,000 R10 13,000 R11 8.000 R12 3,000 (LOW) R13 3,000 R14 586 |
20th Apr 2020, 4:54 pm | #173 |
Rest in Peace
Join Date: Mar 2011
Location: Basildon, Essex, UK.
Posts: 4,100
|
Re: Kolster Brandes 666 Valve radio restoration.
Just a quick note; I have found that KB during this era used wire wound resistors quite frequently and these are often quite close to the original value.
Measuring the resistors whilst connected in circuit may produce some erroneous results because of influences from other components in the circuit. This will generally make the measured value appear lower than it should. In general terms any carbon composition resistors will tend to go high in value with age. So don't go chopping them out unnecessarily just yet. Mike Last edited by crackle; 20th Apr 2020 at 5:05 pm. |
20th Apr 2020, 5:06 pm | #174 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
|
Re: Kolster Brandes 666 Valve radio restoration.
Looking at the measurements so far;-
R1 out of spec. R7 out of spec. R11 just in spec. R12 out of spec. R1 is definitely not shunted DC wise, so I believe the reading to be correct. R7, R11 and R12 are all in the power supply area and I'm not sure whether they're shunted DC wise or not. If R12 is out of spec it will have a profound effect on circuit voltages around V1, V2 and V3 which we know are incorrect. I suggest disconnecting one end of it and then checking it again.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
20th Apr 2020, 5:59 pm | #175 |
Pentode
Join Date: Nov 2019
Location: Tewkesbury, Gloucestershire, UK.
Posts: 173
|
Re: Kolster Brandes 666 Valve radio restoration.
Managed to check the rest very hard to get at a couple
R15 260,000 R16 234,000 R17 300 R18 3000 R19 387 R20 512,000 R21 582 R22 250,000 R23 getting no reading R24 40,000 LOW R25 4135 R26 250,000 R27 135,000 R28 135,000 R29 Unable to find Think i have worked it out correctly but not 100% certain as my vault meter scale is different and need to multiply |
20th Apr 2020, 6:18 pm | #176 |
Pentode
Join Date: Nov 2019
Location: Tewkesbury, Gloucestershire, UK.
Posts: 173
|
Re: Kolster Brandes 666 Valve radio restoration.
just quickly Re-checked R12 Getting reading of 18,000 now still in sittue bit better (spec should be 25,000)
bit better possible had bad connection before , will unsolder and recheck again |
20th Apr 2020, 6:27 pm | #177 |
Pentode
Join Date: Nov 2019
Location: Tewkesbury, Gloucestershire, UK.
Posts: 173
|
Re: Kolster Brandes 666 Valve radio restoration.
R12 unsoldered from mounting now getting a reading of 20,000 (still a bit low) to spec
|
20th Apr 2020, 6:43 pm | #178 |
Pentode
Join Date: Nov 2019
Location: Tewkesbury, Gloucestershire, UK.
Posts: 173
|
Re: Kolster Brandes 666 Valve radio restoration.
Thank you for your help today ,
possibily do some more test tomorrow (have just quickly re-checked R7 again incase i read it faulty or of bad connection still appears low reading )and possibly will continue tomorrow and double check the faulty readings plus any other tests may need doing |
20th Apr 2020, 7:26 pm | #179 |
Pentode
Join Date: Nov 2019
Location: Tewkesbury, Gloucestershire, UK.
Posts: 173
|
Re: Kolster Brandes 666 Valve radio restoration.
Hi
I do have a box full of new resistors all different types ,have attached picture of , but possibly not suitable for this radio but may aswell just check Have attached picture of |
20th Apr 2020, 9:15 pm | #180 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,192
|
Re: Kolster Brandes 666 Valve radio restoration.
It's not always possible for me to respond quickly, I have my own stuff to do as well. Some times I can interrupt this, but not today.
R12 is just in spec. R23 no reading. This is a 2Mohm resistor which is the highest value your meter can measure. There's no way of telling whether it's drifted high or not. R24 is shunted by L4. I'm surprised that the reading is so high. I'd have expected it to be quite low. The reading between L4 points D and E is quoted as 57 ohms. R27 and R28 are shunted by L5, so effectively wired in parallel. Expected reading is 125k, so 135k is OK. R29. This should be connected to the centre tag of the volume control. The time has come when you can't do much more without replacing components. The resistors could be useful if they're the correct values and you don't mind them being physically small when compared to the originals.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |