Bush VHF90: control knobs and tuning scale variations - UK Vintage Radio Repair and Restoration Discussion Forum

dazzlevision · 11th Jun 2018, 2:25 pm

I’ve recently acquired and restored a Bush VHF90, which I think is a very attractive and compact MW/VHF universal mains set.

My example has two dark brown control knobs, which is as shown on the Bush VHF90 service manual’s front cover. However, I have recently seen a VHF90 with two ivory control knobs and different tuning scale colour scheme (maroon and gold).

Does anyone know whether this was an early or late production change? In the Bush VHF90 service manual, there is no mention of two different styles of control knob or tuning scale being fitted.

Perhaps Bush issue one of their little gummed paper service manual amendments stickers (printed in red), to advertise this change?

I can’t decide which version I like the most!

stitch1 · 11th Jun 2018, 9:15 pm

I can’t answer your question but I have a cream knob version and the serial number can be seen on the picture, not sure if from this you can determine if it’s an early or late production change.

John

dazzlevision · 12th Jun 2018, 11:21 am

Quote:

Originally Posted by stitch1

I can’t answer your question but I have a cream knob version and the serial number can be seen on the picture, not sure if from this you can determine if it’s an early or late production change.

John

Thank you for replying.

My set's serial number is 206/09228, so yours (206/31723) would seem to be a much later production set.

So, the change to ivory control knobs and a gold/maroon tuning scale would appear to be a later production change, unless Bush decided to offer a choice of presentation parts finishes…?

stitch1 · 12th Jun 2018, 12:57 pm

So the search is on to find a cream on cream version with a lower number than yours, anyone

John

MurphyNut · 14th Jun 2018, 12:28 pm

Annoyingly I passed on one of these cream ones some years ago and now regret it, (how often have you heard or done that!) They are attractive sets.
They did the Bush VHF90 in brown and black Bakelite cases too, there is a possibility someone might have swapped the chassis over. My Black set has the same dial/knobs as the cream one shown.

Boater Sam · 14th Jun 2018, 2:17 pm

My cream VHF90 is buried in the "to be completed" racks at present but I know it to have cream knobs and the (broken) maroon on gold tuning scale.

crusher19860138 · 16th Jun 2018, 9:40 pm

A very troublesome set, and a nightmare to work on, power resistors mounted underneath the chassis, with the resultant heat cooking just about everything in sight!

dazzlevision · 16th Jun 2018, 10:11 pm

Quote:

Originally Posted by crusher19860138

......Power resistors mounted underneath the chassis, with the resultant heat cooking just about everything in sight!

True enough, but luckily, some many years ago, my set has had the wirewound 150 Ohm UY85 surge limiter resistor replaced by a long "Radiospares" 100 Ohm w/w resistor, wired directly between the tagstrip and the UY85 valveholder's anode pin. The Paxolin/SRBP material of the tagstrip is therefore only slightly darkened.

So, the incorrect value replacement resistor dissipates a lot less power (but the surge current as the UY85 starts to pass current, will be higher than the original design allowed for).

As suggested elsewhere in this Forum, I relocated the resistor (with one of the correct value) to the rear of the mains adjustment panel "on top". I have checked that the heat from it does not cause a worrying temperature rise material of the moulded cabinet above it.

Boater Sam · 17th Jun 2018, 1:52 pm

If this is a cream cabinet, I would advise you to fit a heat reflector inside under the top above that resistor, a bit of shiny foil should do, as the cabinets discolour and split very quickly.

dazzlevision · 17th Jun 2018, 1:59 pm

Quote:

Originally Posted by Boater Sam

If this is a cream cabinet, I would advise you to fit a heat reflector inside under the top above that resistor, a bit of shiny foil should do, as the cabinets discolour and split very quickly.

Thanks for the tip. I don't intend to use this set for everyday listening, but I'll see what I have in "stores" to make up such an item - just in case.

MurphyNut · 18th Jun 2018, 4:17 pm

Quote:

Originally Posted by Boater Sam

If this is a cream cabinet, I would advise you to fit a heat reflector inside under the top above that resistor, a bit of shiny foil should do, as the cabinets discolour and split very quickly.

So true, cream Bakelite is much more prone to fracturing than brown and black when exposed to heat.

11th Jun 2018, 2:25 pm	#1
dazzlevision Dekatron Join Date: Sep 2003 Location: Near Swindon, North Wiltshire, UK. Posts: 3,608	Bush VHF90: control knobs and tuning scale variations I’ve recently acquired and restored a Bush VHF90, which I think is a very attractive and compact MW/VHF universal mains set. My example has two dark brown control knobs, which is as shown on the Bush VHF90 service manual’s front cover. However, I have recently seen a VHF90 with two ivory control knobs and different tuning scale colour scheme (maroon and gold). Does anyone know whether this was an early or late production change? In the Bush VHF90 service manual, there is no mention of two different styles of control knob or tuning scale being fitted. Perhaps Bush issue one of their little gummed paper service manual amendments stickers (printed in red), to advertise this change? I can’t decide which version I like the most! Attached Thumbnails

11th Jun 2018, 9:15 pm	#2
stitch1 Heptode Join Date: Jan 2008 Location: Durham, County Durham, UK. Posts: 826	Re: Bush VHF90: control knobs and tuning scale variations I can’t answer your question but I have a cream knob version and the serial number can be seen on the picture, not sure if from this you can determine if it’s an early or late production change. John Attached Thumbnails Last edited by stitch1; 11th Jun 2018 at 9:27 pm. Reason: Spelling!

12th Jun 2018, 12:57 pm	#4
stitch1 Heptode Join Date: Jan 2008 Location: Durham, County Durham, UK. Posts: 826	Re: Bush VHF90: control knobs and tuning scale variations So the search is on to find a cream on cream version with a lower number than yours, anyone John

14th Jun 2018, 12:28 pm	#5
MurphyNut Heptode Join Date: Apr 2016 Location: Croxley Green, Hertfordshire, UK. Posts: 979	Re: Bush VHF90: control knobs and tuning scale variations Annoyingly I passed on one of these cream ones some years ago and now regret it, (how often have you heard or done that!) They are attractive sets. They did the Bush VHF90 in brown and black Bakelite cases too, there is a possibility someone might have swapped the chassis over. My Black set has the same dial/knobs as the cream one shown. __________________ Clive

14th Jun 2018, 2:17 pm	#6
Boater Sam Banned Join Date: Dec 2013 Location: Middlewich, Cheshire, UK. & Winter in the Philippines. Posts: 3,897	Re: Bush VHF90: control knobs and tuning scale variations My cream VHF90 is buried in the "to be completed" racks at present but I know it to have cream knobs and the (broken) maroon on gold tuning scale.

16th Jun 2018, 9:40 pm	#7
crusher19860138 Hexode Join Date: Sep 2010 Location: Stourbridge, West Midlands, UK. Posts: 434	Re: Bush VHF90: control knobs and tuning scale variations A very troublesome set, and a nightmare to work on, power resistors mounted underneath the chassis, with the resultant heat cooking just about everything in sight!

17th Jun 2018, 1:52 pm	#9
Boater Sam Banned Join Date: Dec 2013 Location: Middlewich, Cheshire, UK. & Winter in the Philippines. Posts: 3,897	Re: Bush VHF90: control knobs and tuning scale variations If this is a cream cabinet, I would advise you to fit a heat reflector inside under the top above that resistor, a bit of shiny foil should do, as the cabinets discolour and split very quickly.