Philips Type 310A IF coil question - UK Vintage Radio Repair and Restoration Discussion Forum

pentoad · 27th Oct 2021, 7:30 pm

This set has not been tested yet, as there is some time and expense required to get it to that stage
The original first IF coil has been replaced at some point by a radio spares type1 465Kc/s as in the photo, however the original has tap at S17/S18 shown on the second photo so the replacement is not the same spec as the original, and I don't whether it was a successful repair, although it is wired correctly.
Would it function properly with that radio spares replacement?

Herald1360 · 27th Oct 2021, 8:38 pm

Probably. There might be a slight difference in IF bandwidth and/or overall sensitivity. The set has some typical "Philipsisms" in its design, this is yet another.

Sideband · 27th Oct 2021, 10:07 pm

It would certainly function and it might not make any noticeable difference to the average casual user. It might affect selectivity slightly but possibly not enough to really matter particularly now MW is somewhat less crowded than it was.

pentoad · 28th Oct 2021, 2:15 pm

Thank you for your replies which has inspired me to go ahead with a restoration. The only thing that concerns me is that the black pitch covered caps are values which seem difficult to obtain, my guess is that are all leaky to some extent.

telstar · 28th Oct 2021, 2:45 pm

Quote:

Originally Posted by pentoad

Thank you for your replies which has inspired me to go ahead with a restoration. The only thing that concerns me is that the black pitch covered caps are values which seem difficult to obtain, my guess is that are all leaky to some extent.

Hi. The best thing to do is remove and replace them with modern capacitors rated at 500 volts plus. Someone in Holland once informed me that they never functioned properly (the pitch coated capacitors).

Herald1360 · 28th Oct 2021, 4:49 pm

Unless a capacitor is used in a critically frequency conscious application, its replacement's value can reasonably be anywhere within 20% of the original. Generally higher is better than lower.

Ed_Dinning · 28th Oct 2021, 7:14 pm

Note that these Philips pitch covered caps can be replaced with "nearest value" equivalents, 0.47 for 0.5 etc as long as the voltage rating is suitable. In many cases a higher cap value will work without problems. If the values are not visible then cross check from the schematic

Ed

pentoad · 29th Oct 2021, 7:50 pm

I am replacing the black caps with modern equivalents as none of them are right

27th Oct 2021, 7:30 pm	#1
pentoad Hexode Join Date: Feb 2011 Location: Newcastle upon Tyne, Tyne and Wear, UK. Posts: 280	Philips Type 310A IF coil question This set has not been tested yet, as there is some time and expense required to get it to that stage The original first IF coil has been replaced at some point by a radio spares type1 465Kc/s as in the photo, however the original has tap at S17/S18 shown on the second photo so the replacement is not the same spec as the original, and I don't whether it was a successful repair, although it is wired correctly. Would it function properly with that radio spares replacement? Attached Thumbnails

27th Oct 2021, 8:38 pm	#2
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: Philips Type 310A IF coil question Probably. There might be a slight difference in IF bandwidth and/or overall sensitivity. The set has some typical "Philipsisms" in its design, this is yet another. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

27th Oct 2021, 10:07 pm	#3
Sideband Dekatron Join Date: Oct 2003 Location: Croydon, Surrey, UK. Posts: 7,580	Re: Philips Type 310A IF coil question It would certainly function and it might not make any noticeable difference to the average casual user. It might affect selectivity slightly but possibly not enough to really matter particularly now MW is somewhat less crowded than it was. __________________ There are lots of brilliant keyboard players and then there is Rick Wakeman.....

28th Oct 2021, 2:15 pm	#4
pentoad Hexode Join Date: Feb 2011 Location: Newcastle upon Tyne, Tyne and Wear, UK. Posts: 280	Re: Philips Type 310A IF coil question Thank you for your replies which has inspired me to go ahead with a restoration. The only thing that concerns me is that the black pitch covered caps are values which seem difficult to obtain, my guess is that are all leaky to some extent.

28th Oct 2021, 4:49 pm	#6
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: Philips Type 310A IF coil question Unless a capacitor is used in a critically frequency conscious application, its replacement's value can reasonably be anywhere within 20% of the original. Generally higher is better than lower. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

28th Oct 2021, 7:14 pm	#7
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,195	Re: Philips Type 310A IF coil question Note that these Philips pitch covered caps can be replaced with "nearest value" equivalents, 0.47 for 0.5 etc as long as the voltage rating is suitable. In many cases a higher cap value will work without problems. If the values are not visible then cross check from the schematic Ed

29th Oct 2021, 7:50 pm	#8
pentoad Hexode Join Date: Feb 2011 Location: Newcastle upon Tyne, Tyne and Wear, UK. Posts: 280	Re: Philips Type 310A IF coil question I am replacing the black caps with modern equivalents as none of them are right