|
Vintage Radio (domestic) Domestic vintage radio (wireless) receivers only. |
|
Thread Tools |
13th Aug 2018, 5:23 am | #1 |
Diode
Join Date: Aug 2018
Location: Nelson, New Zealand
Posts: 9
|
Philips V7A tunes backwards
I recently bought a Philips V7A at auction, and have started work on it. Just a bit of cleaning has enabled it to work, on medium wave at least, and it sounds very nice. The dial shows New Zealand stations. However, there’s something odd (even odder than usual for this set, perhaps). The frequency scale increases from right to left, but the tuning is clearly going from left to right! I can only suppose that someone has restrung it incorrectly in the past. After reading earlier comments on this forum about the similar V5A, I view the prospect of correcting this with trepidation. Can anyone comment or help, please? What I really need is a nice YouTube video showing exactly what to do... Thanks!
|
13th Aug 2018, 10:46 am | #2 |
Rest in Peace
Join Date: Mar 2011
Location: Basildon, Essex, UK.
Posts: 4,100
|
Re: Philips V7A tunes backwards
Hi, welcome from the UK.
Check to see that the tuning capacitor vanes are fully open (unmeshed) when the dial pointer is turned to indicate the high frequency end of the dial. If the dial is marked in "wavelength" then the high frequency end of the dial is the end with the lowest numbers. If this is not the case and the tuning cap is fully meshed when the dial is indicating the high frequency end of the dial then you have a problem which needs rectifying. Please report back. Mike |
13th Aug 2018, 11:13 am | #3 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
|
Re: Philips V7A tunes backwards
I checked the service data from VRSD for this radio. Alas there is no threading diagram.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
13th Aug 2018, 11:21 am | #4 |
Dekatron
Join Date: Apr 2011
Location: Cornwall, UK.
Posts: 13,454
|
Re: Philips V7A tunes backwards
Some stringing info for a V5a here...might be similar?:
https://www.vintage-radio.net/forum/...ad.php?t=16826 Lawrence. |
13th Aug 2018, 2:04 pm | #5 |
Rest in Peace
Join Date: Nov 2010
Location: North Hykeham, Lincolnshire, UK.
Posts: 515
|
Re: Philips V7A tunes backwards
Most drive cord layouts are simple and straightforward, making them easy to restring, but Philips' drive cords are the work of Satan!
Mixtures of nylon cord and stranded steel wire, multi-section pulleys, intermediate pulleys, separate cords/wires for tuning and pointer - you name it, they did it! We had a theory that there was a fiendishly intelligent inmate of the Eindhoven mental hospital who was let out once a year to devise a new scheme for the next range of Philips sets! |
13th Aug 2018, 9:48 pm | #6 |
Heptode
Join Date: Feb 2006
Location: Marlborough, Wiltshire, UK.
Posts: 917
|
Re: Philips V7A tunes backwards
Restringing one of these is not too bad once you loosen off the wooden base to improve access. The base can be eased away as far as the wiring allows. There are no real nasties such as Bowden cables. Lubricate the pivots, especially on the arm carrying the pointer. Check the base for woodworm while you are in there !
Ken |
13th Aug 2018, 11:09 pm | #7 |
Dekatron
Join Date: Jan 2003
Location: Bradford on Avon, Wiltshire, UK.
Posts: 3,310
|
Re: Philips V7A tunes backwards
Maybe the set is correct but someone has put the "wrong" tuning scale on.
__________________
"Nothing is as dangerous as being too modern;one is apt to grow old fashioned quite suddenly." |
13th Aug 2018, 11:14 pm | #8 | |
Dekatron
Join Date: May 2010
Location: Greater Manchester, UK.
Posts: 18,724
|
Re: Philips V7A tunes backwards
Quote:
As Mike says in Post #2, the increasing scale R to L typically 200 - 550 is wavelength in metres, which is of course the inverse of frequency. How does that compare with yours? Image came from https://www.the-saleroom.com/en-gb/a...d-a5aa010ba7ba
__________________
-- Graham. G3ZVT Last edited by Graham G3ZVT; 13th Aug 2018 at 11:25 pm. |
|
14th Aug 2018, 5:18 am | #9 |
Diode
Join Date: Aug 2018
Location: Nelson, New Zealand
Posts: 9
|
Re: Philips V7A tunes backwards
Many thanks to all for the responses. I checked the scale and frequency definitely increases right to left on all three bands, with wavelength obviously going the other way. There wasn’t enough resolution on the image posted for me to see for sure, but if the UK version had frequency increasing left to right, that’s very interesting. I will post an image of the NZ scale but need to shrink the image slightly to meet the constraints of the site.
There are two strong medium wave stations here: TAB Radio near the middle of the band, and National Radio (yes, we still have a National Programme in this country!) about 200 kHz higher in frequency. The Theatrette receives both of these, but places National to the right of TAB, i.e., it is claiming National is on a lower frequency, which is not the case. Many thanks for the diagram showing stringing for the V5A, which potentially is very helpful indeed. Thanks too for the tip about removing the wooden base. I’m wondering whether I can solve the problem by moving the pointer from one horizontal cord to the other, which would move in the opposite direction, but being Philips I suspect it won’t be so simple. Such a contrast, isn’t it, between the pleasingly simple lines outside, and the crazy interior! |
14th Aug 2018, 6:48 am | #10 | |
Rest in Peace
Join Date: Mar 2011
Location: Basildon, Essex, UK.
Posts: 4,100
|
Re: Philips V7A tunes backwards
Quote:
But I wonder if in New Zealand they used metres on the dial at all. It is quite possible in that part of the world and Australia they did not put any numbers on the dial, just station abbreviations, I have seen this on later models. Mike |
|
14th Aug 2018, 7:01 am | #11 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
|
Re: Philips V7A tunes backwards
If you open the link and look at the pictures it's quite easy to see that 200 metres is on the left as you deduced.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
14th Aug 2018, 7:55 am | #12 |
Diode
Join Date: Aug 2018
Location: Nelson, New Zealand
Posts: 9
|
Re: Philips V7A tunes backwards
Here are the images as promised. The back view shows a 'before' view. You can see that it has been serviced fairly unsympathetically in the past.
The closeup view of the scale shows that kc/s increase from 550 on the right, to 1500 on the left. At present, when the pointer is at the left, this corresponds to the tuning capacitor plates being fully enmeshed, that is, lowest frequency. I really don't want to restring it if I can avoid it. I will try shifting the pointer from one string to the other as I said, but I'm not sure if the slider mechanism will get in the way of this. Does anyone know a source of the female mains plugs for this model? Thanks again Lawrence -- |
14th Aug 2018, 8:32 am | #13 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
|
Re: Philips V7A tunes backwards
The sense of that scale is exactly the same as the UK version, except that yours is marked in kc/s rather than metres.
As I'm sure you're aware, wavelength in metres times frequency in kc/s is 300,000. 1500 kc/s is 200 metres and 550kc/s is 545 metres. If the tuning capacitor vanes are fully meshed at 1500 kc/s, then the pointer is indeed moving in the wrong direction.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
14th Aug 2018, 9:12 am | #14 |
Octode
Join Date: Sep 2004
Location: St. Albans, Hertfordshire, UK.
Posts: 1,478
|
Re: Philips V7A tunes backwards
I can't go through the mental thought processes required at this time of the morning, but is this a case of the tuning capacitor being set 180 degs. out from the tuning drum?
__________________
Regards, Richard, BVWS member |
14th Aug 2018, 9:33 am | #15 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
|
Re: Philips V7A tunes backwards
I think if that were the case either the tuning cap or the scale pointer would jam when the tuning control was rotated.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
14th Aug 2018, 9:41 am | #16 |
Rest in Peace
Join Date: Sep 2010
Location: Ripley, Derbyshire, UK.
Posts: 785
|
Re: Philips V7A tunes backwards
Does it not come down to the dial cord being threaded in the wrong direction around the tuning capacitor drum? Tony.
|
14th Aug 2018, 9:44 am | #17 |
Banned
Join Date: Dec 2013
Location: Middlewich, Cheshire, UK. & Winter in the Philippines.
Posts: 3,897
|
Re: Philips V7A tunes backwards
I would think that boxdoctor is correct.
But does the pointer move in the expected direction when turning the tuning knob? Or is that A about F as well? Sam. |
14th Aug 2018, 9:49 am | #18 |
Heptode
Join Date: Feb 2006
Location: Marlborough, Wiltshire, UK.
Posts: 917
|
Re: Philips V7A tunes backwards
Just done a sanity (my sanity as I could not remember!) check on my V7A. The scale is only marked in wavelength and increases from left to right, as others have commented above.
Ken |
14th Aug 2018, 10:06 am | #19 |
Moderator
Join Date: Jan 2003
Location: Ipswich, Suffolk, IP4, UK.
Posts: 21,289
|
Re: Philips V7A tunes backwards
I don't know about the V7A, but there are some radios where the pointer moves in the opposite direction to that in which the knob is turned.
__________________
Graham. Forum Moderator Reach for your meter before you reach for your soldering iron. |
14th Aug 2018, 10:29 am | #20 |
Heptode
Join Date: Feb 2006
Location: Marlborough, Wiltshire, UK.
Posts: 917
|
Re: Philips V7A tunes backwards
Very true, my V7A swings the pointer left to right for anti-clockwise rotation of the tuning knob.
Ken |