Bush VHF61 Valves - UK Vintage Radio Repair and Restoration Discussion Forum

wheresthetubes · 15th Dec 2009, 11:41 pm

Hello, I have a Bush VHF61 which takes the following valves; ECC85, ECH81,
2x EF89's, EABC80, EL84, EZ80, and a magic eye EM81. Can anyone advise which of these valves are likely to go faulty over time, as I'm looking to buy some NOS valves to put aside.

Steve_P · 15th Dec 2009, 11:48 pm

Those valves rarely fail, but keep an EZ80 (Or EZ81 maybe) with these, and an EL84. But do replace a few capacitors - the capacitor known as 'that capacitor' in particular. And an ECC85 maybe?

Cheers,

Steve P.

Leon Crampin · 16th Dec 2009, 12:08 am

In order of unreliability (most unreliable first) EM81 (fades out); ECC85; EL84 (grid current); EF89s (low emission); EABC80 (FM diode match); ECH81.

The EZ80s in Bush sets last well because the BEC electrolytics don't usually fail.

All the valves except the EM81 are easy to get, so are hardly worth stockpiling. To maintain FM functionality, I'd just get a spare ECC85 if all the others are in good shape. If you restore these sets properly, they're not heavy on valves.

Leon.

Steve_P · 16th Dec 2009, 12:18 am

EM80/81 available for £10 each from Past Times Radio.

Cheers,

Steve P.

dr peppers · 16th Dec 2009, 5:02 am

I'm not totally sure 'bout this, but I think the ecc85 is the rf input pre amp for the vhf band.
Some sources say this particular valve on a vhf set should be replaced as a matter of course on a restoration as it degrades (is this because its operating in common cathode?), my philco has an equivalent and it certainly improved vhf sensitivity when it was replaced.

wheresthetubes · 16th Dec 2009, 9:01 am

Many thanks for this info, very helpful. I'll be buying a EM81 and an ECC85 in the near future.

monoman · 16th Dec 2009, 9:24 am

The ECC85 kept failing in my VHF64. This turned out to be due to low heater voltage (<5V) caused by poor connection to chassis of the heater return at the transformer. Worth remaking this connection with a star washer to cut through the oxidation.

Brian.

Leon Crampin · 16th Dec 2009, 4:38 pm

The VHF61 was built to the traditional standards of Bush, which included the fitment of shakeproof washers under every nut. Earthing problems are uncommon on these sets.

The VHF64 has no spring washers - the British rot was starting to develop. Earthing faults, including that of the chassis end plate carrying the smoothing capacitors, are quite common. It was also designed with unacceptable mains hum and requires modifications to make it work well.

Leon.

wheresthetubes · 16th Dec 2009, 7:57 pm

Funny that, I always thought the VHF64 was technically superior to the VHF61. My preference for the VHF61 was based purely on its bakelite case.

telstar · 16th Dec 2009, 8:07 pm

Hi. The EF89 valves on my Bush VHF61 had low gain, and when I managed to find replacements for them, it improved the o/p from the radio. You may as well add these valves to your list of requirements.
Regards
Mike

georgesgiralt · 17th Dec 2009, 10:11 am

Hi !
I keep a lot of NOS valves to ascertain I can run every set in my little collection in distant future.
Of course, I do not have a complete spare set for every radio I own, but a couple of valve of every model used in my sets. Except for the ECC85 of which I have 10 (bought them all together).
IMHO, keep the new EM81 in the drawer. Fading of the magic eye will not put your set out of use. Shading the display with your hand is enough to make the tuning.
As per lifespan of valves, it is really dependant on the set. My Ducretet Thomson of 1957 still run every day with it's original set as do my Blaupunkt of the same vintage. I've a Grundig which eats ECL86 regularly whatever checks you perform. I've got a Braun SK25 which was used and abused. during restoration, I get the set of valves to a fellow which owns a big Metrix valve tester as the set had all the originals. All passed with flying colours, even the EL95 !
So do not rush to by your stock, wait for some kind of deal ...
Regards.

15th Dec 2009, 11:41 pm	#1
wheresthetubes Retired Dormant Member Join Date: Jul 2009 Location: Reading, Berkshire, UK. Posts: 135	Bush VHF61 Valves Hello, I have a Bush VHF61 which takes the following valves; ECC85, ECH81, 2x EF89's, EABC80, EL84, EZ80, and a magic eye EM81. Can anyone advise which of these valves are likely to go faulty over time, as I'm looking to buy some NOS valves to put aside.

15th Dec 2009, 11:48 pm	#2
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Bush VHF61 Valves Those valves rarely fail, but keep an EZ80 (Or EZ81 maybe) with these, and an EL84. But do replace a few capacitors - the capacitor known as 'that capacitor' in particular. And an ECC85 maybe? Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

16th Dec 2009, 12:08 am	#3
Leon Crampin Octode Join Date: Nov 2005 Location: Surrey, UK. Posts: 1,874	Re: Bush VHF61 Valves In order of unreliability (most unreliable first) EM81 (fades out); ECC85; EL84 (grid current); EF89s (low emission); EABC80 (FM diode match); ECH81. The EZ80s in Bush sets last well because the BEC electrolytics don't usually fail. All the valves except the EM81 are easy to get, so are hardly worth stockpiling. To maintain FM functionality, I'd just get a spare ECC85 if all the others are in good shape. If you restore these sets properly, they're not heavy on valves. Leon.

16th Dec 2009, 12:18 am	#4
Steve_P Dekatron Join Date: Sep 2003 Location: Bolton, Greater Manchester, UK. Posts: 6,644	Re: Bush VHF61 Valves EM80/81 available for £10 each from Past Times Radio. Cheers, Steve P. __________________ If we've always had it, why is the Car Boot open? You're not sneaking another Old TV in are you...?

16th Dec 2009, 5:02 am	#5
dr peppers Retired Dormant Member Join Date: Nov 2009 Location: Lancashire, UK. Posts: 67	Re: Bush VHF61 Valves I'm not totally sure 'bout this, but I think the ecc85 is the rf input pre amp for the vhf band. Some sources say this particular valve on a vhf set should be replaced as a matter of course on a restoration as it degrades (is this because its operating in common cathode?), my philco has an equivalent and it certainly improved vhf sensitivity when it was replaced.

16th Dec 2009, 9:01 am	#6
wheresthetubes Retired Dormant Member Join Date: Jul 2009 Location: Reading, Berkshire, UK. Posts: 135	Re: Bush VHF61 Valves Many thanks for this info, very helpful. I'll be buying a EM81 and an ECC85 in the near future.

16th Dec 2009, 9:24 am	#7
monoman Retired Dormant Member Join Date: Jan 2008 Location: Ongar, Essex, UK. Posts: 74	Re: Bush VHF61 Valves The ECC85 kept failing in my VHF64. This turned out to be due to low heater voltage (<5V) caused by poor connection to chassis of the heater return at the transformer. Worth remaking this connection with a star washer to cut through the oxidation. Brian.

16th Dec 2009, 4:38 pm	#8
Leon Crampin Octode Join Date: Nov 2005 Location: Surrey, UK. Posts: 1,874	Re: Bush VHF61 Valves The VHF61 was built to the traditional standards of Bush, which included the fitment of shakeproof washers under every nut. Earthing problems are uncommon on these sets. The VHF64 has no spring washers - the British rot was starting to develop. Earthing faults, including that of the chassis end plate carrying the smoothing capacitors, are quite common. It was also designed with unacceptable mains hum and requires modifications to make it work well. Leon.

16th Dec 2009, 7:57 pm	#9
wheresthetubes Retired Dormant Member Join Date: Jul 2009 Location: Reading, Berkshire, UK. Posts: 135	Re: Bush VHF61 Valves Funny that, I always thought the VHF64 was technically superior to the VHF61. My preference for the VHF61 was based purely on its bakelite case.

16th Dec 2009, 8:07 pm	#10
telstar Octode Join Date: Dec 2003 Location: Leeds, West Yorkshire, UK. Posts: 1,592	Re: Bush VHF61 Valves Hi. The EF89 valves on my Bush VHF61 had low gain, and when I managed to find replacements for them, it improved the o/p from the radio. You may as well add these valves to your list of requirements. Regards Mike

17th Dec 2009, 10:11 am	#11
georgesgiralt Hexode Join Date: Jul 2008 Location: Toulouse, France Posts: 406	Re: Bush VHF61 Valves Hi ! I keep a lot of NOS valves to ascertain I can run every set in my little collection in distant future. Of course, I do not have a complete spare set for every radio I own, but a couple of valve of every model used in my sets. Except for the ECC85 of which I have 10 (bought them all together). IMHO, keep the new EM81 in the drawer. Fading of the magic eye will not put your set out of use. Shading the display with your hand is enough to make the tuning. As per lifespan of valves, it is really dependant on the set. My Ducretet Thomson of 1957 still run every day with it's original set as do my Blaupunkt of the same vintage. I've a Grundig which eats ECL86 regularly whatever checks you perform. I've got a Braun SK25 which was used and abused. during restoration, I get the set of valves to a fellow which owns a big Metrix valve tester as the set had all the originals. All passed with flying colours, even the EL95 ! So do not rush to by your stock, wait for some kind of deal ... Regards.