Another Grundig Concert Boy 1100 thread - UK Vintage Radio Repair and Restoration Discussion Forum

WaveyDipole · 9th Jan 2016, 6:18 pm

I have just purchased one of those from a member and it is in good cosmetic contdition and seems to work well on all bands. However, there are a couple of issues I wanted to check on.

1. It has a selenium rectifier. It is working fine off mains so is it a case of 'if it ain't broke don't fix it', or is it best to replace these?

2. The switches on two of the wavebands are temperamental. I have tried squirting a bit of servisol down them (having found a small gap near the top) but this does not seem to have helped much. Is there anything else that can be done with these? Is it possible to get replacements?

FM sounds great until you turn the volume of to about halfway or more, when it starts to distort. It is very loud though. I don't notice the problem with AM which has less volume by comparison, particularly on the SW bands. I'm not sure whether this has to do with the relative strength of output from the FM section which is causing the amp to clip at higher volumes or whether the speaker to is getting overwhelmed with excessive power from the amp, but I will investigate this further. I will first try it with an external speaker and see how it sounds.

In the meantime I would appreciate any insight on the two issues above.

WaveyDipole · 9th Jan 2016, 9:23 pm

I should perhaps also point out that this radio is in good cosmetic condition and internally appears to be untouched, so all in all a good unmolested example of this set. I was anticipating making fairly regular use of it, hence was thinking about preventative maintenance, but perhaps on second thoughts, it it better to preserve it in its original state?

Leon Crampin · 10th Jan 2016, 7:05 pm

I would say that the performance of your radio is normal. Mine has perhaps too much audio gain on FM. The Se rectifiers don't give trouble unless overloaded, and in any case there is a fuse. Mine is original.

Perhaps the most important preventative maintenance is to apply light oil to the gang and tuning spindle bearings. The spindle bearing will seize as the original lubricant hardens. The switches are noise prone if not used - so the SW switches on mine have given the most trouble. Servisol seems to have little effect - use is better.

These are excellent sets, but prone to rattles at high volume - there are too few screws securing the back. Strategically applied felt inside the case mitigates the rattles.

Leon.

WaveyDipole · 20th Jan 2016, 11:21 pm

Leon, thanks. That is helpful information. I guess the switches will just need to get worked a bit more. The tuning gang seems to work very well, but I will check it out and oil it if needed.

9th Jan 2016, 6:18 pm	#1
WaveyDipole Nonode Join Date: Mar 2013 Location: Leicester, UK Posts: 2,535	Another Grundig Concert Boy 1100 thread I have just purchased one of those from a member and it is in good cosmetic contdition and seems to work well on all bands. However, there are a couple of issues I wanted to check on. 1. It has a selenium rectifier. It is working fine off mains so is it a case of 'if it ain't broke don't fix it', or is it best to replace these? 2. The switches on two of the wavebands are temperamental. I have tried squirting a bit of servisol down them (having found a small gap near the top) but this does not seem to have helped much. Is there anything else that can be done with these? Is it possible to get replacements? FM sounds great until you turn the volume of to about halfway or more, when it starts to distort. It is very loud though. I don't notice the problem with AM which has less volume by comparison, particularly on the SW bands. I'm not sure whether this has to do with the relative strength of output from the FM section which is causing the amp to clip at higher volumes or whether the speaker to is getting overwhelmed with excessive power from the amp, but I will investigate this further. I will first try it with an external speaker and see how it sounds. In the meantime I would appreciate any insight on the two issues above.

9th Jan 2016, 9:23 pm	#2
WaveyDipole Nonode Join Date: Mar 2013 Location: Leicester, UK Posts: 2,535	Re: Another Grundig Concert Boy 1100 thread I should perhaps also point out that this radio is in good cosmetic condition and internally appears to be untouched, so all in all a good unmolested example of this set. I was anticipating making fairly regular use of it, hence was thinking about preventative maintenance, but perhaps on second thoughts, it it better to preserve it in its original state?

10th Jan 2016, 7:05 pm	#3
Leon Crampin Octode Join Date: Nov 2005 Location: Surrey, UK. Posts: 1,874	Re: Another Grundig Concert Boy 1100 thread I would say that the performance of your radio is normal. Mine has perhaps too much audio gain on FM. The Se rectifiers don't give trouble unless overloaded, and in any case there is a fuse. Mine is original. Perhaps the most important preventative maintenance is to apply light oil to the gang and tuning spindle bearings. The spindle bearing will seize as the original lubricant hardens. The switches are noise prone if not used - so the SW switches on mine have given the most trouble. Servisol seems to have little effect - use is better. These are excellent sets, but prone to rattles at high volume - there are too few screws securing the back. Strategically applied felt inside the case mitigates the rattles. Leon.

20th Jan 2016, 11:21 pm	#4
WaveyDipole Nonode Join Date: Mar 2013 Location: Leicester, UK Posts: 2,535	Re: Another Grundig Concert Boy 1100 thread Leon, thanks. That is helpful information. I guess the switches will just need to get worked a bit more. The tuning gang seems to work very well, but I will check it out and oil it if needed.