16th Sep 2016, 4:52 pm | #1 |
Heptode
Join Date: Nov 2008
Location: North Walsham, Norfolk, UK.
Posts: 900
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Bush VHF70
I bought this one non working ages ago but after changing various caps and a couple of resistors I could only get the audio stages working nothing from the RF side, fast forward 3 years and it's a rainy afternoon all the paying jobs waiting for spares so I thought I would have another look. When I took the back off I found the UF89 had gone all white hmmmm wasn't like that before.
I checked for mains continuity and found the rubber wires to the panel lamps were all crumbled both lamps and the 30 ohm resistor open so I wired in a 100 ohm dropper as that's all I had to hand and tried it. To my surprise it works well on MW LW and even VHF though when tuned into a station on FM it has a nasty background hum. The UF89 must have been faulty all along so it pays to leave it and go back sometimes. Oh and does anyone know what the panel lamps are as I can read 3.5 volt on them but not the current and the service data doesn't say. |
16th Sep 2016, 5:02 pm | #2 |
Rest in Peace
Join Date: May 2003
Location: Harlaxton, Lincolnshire, UK.
Posts: 3,944
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Re: Bush VHF70
The dial lamps are listed on the last page of the manufacturer's manual as 3.5V 0.15A.
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16th Sep 2016, 5:06 pm | #3 |
Dekatron
Join Date: Jun 2015
Location: Biggin Hill, London, UK.
Posts: 5,215
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Re: Bush VHF70
Trader Sheet 1419 (which covers this set) says that the bulbs are 3.5V, 0.15A
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26th Oct 2016, 4:04 pm | #4 |
Heptode
Join Date: Nov 2008
Location: North Walsham, Norfolk, UK.
Posts: 900
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Re: Bush VHF70
Just to put this one to bed I at last had time to work on this again. I gave up trying to find lamps at a decent price, higher current ones hardly glowed, so I went down the led route I bought 50 surface mount 1 watt ones a while ago for a couple of quid so pressed 2 of them into use with 680R load resistors and they are really good wired in where the old Lamps connected and they even look good, not too white.
As for the strange hummy sounding FM, I had a good look around for the backwards connected electrolytic (not sure of it's name) C54 after much searching I found it wasn't there ?? so I fitted a new one and was rewarded with brilliant FM performance. I found the internal aerial not very good but a couple of feet of wire shoved in one pole of the socket pulls in all the local stations at good volume. A quick polish up and now it's in it's new home on the kitchen windowsill. Only took 3 years lol. |
26th Oct 2016, 4:49 pm | #5 |
Heptode
Join Date: Sep 2013
Location: Manchester, UK.
Posts: 862
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Re: Bush VHF70
3 years? That's not bad going by my standards! It does look good with the L.E.D.s. What 's the supply voltage for the lights?
Regards, Paul
__________________
...No, it's not supposed to pick up the World Service, it's not a radio! |
30th Oct 2016, 8:51 pm | #6 |
Heptode
Join Date: Nov 2008
Location: North Walsham, Norfolk, UK.
Posts: 900
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Re: Bush VHF70
Hi Paul. I have to have the back off again as it starts cracking on VHF after being on a long while so I will measure the supply volts while I am there, wont be till later in the week though,
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30th Oct 2016, 9:23 pm | #7 |
Banned
Join Date: Dec 2013
Location: Middlewich, Cheshire, UK. & Winter in the Philippines.
Posts: 3,897
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Re: Bush VHF70
I did a VHF61 with LEDs, running on AC, and that one started to crackle after an hour or so..................
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30th Oct 2016, 9:53 pm | #8 |
Heptode
Join Date: Nov 2008
Location: North Walsham, Norfolk, UK.
Posts: 900
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Re: Bush VHF70
I wonder if there's a connection ?
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