Strange telefunken shortwave problem HELP!!!!! - UK Vintage Radio Repair and Restoration Discussion Forum

grizzy68 · 2nd Jan 2006, 7:37 am

Hello, I am having some really wierd things happing with my telefunken opus 7. I hooked up an antenna to the shortwave and found that I get a lot of stations around the world, but there is a dial for sw/am and a dial for fm. When I find a sw station and I turn the fm dial it affects the tuning on shortwave for better or worse. Why is this happing? I also notice the sound is better on sw, less destortion. When I tune in a fm station I can get it in clear, but there is destortion when I turn up the volume. Is there a relationship to the two bands?
Thanks
David

ukcol · 2nd Jan 2006, 10:53 am

With regard to the first effect you mention, this is probably normal. I don't know the Opus 7 but I would be prepared to bet that the FM tuning is used to provide a band-spread function on SW. That is, you carry out a course tune to the required SW station with the SW tuning knob and scale and then fine tune using the band-spread function provided by the FM tuning scale and knob. If you look closely at the FM scale there is probably an additional scale besides the normal VHF one.

The distortion on FM is probably a quite separate problem.

grizzy68 · 4th Jan 2006, 4:25 am

What do you think is causing the destortion in the fm & volume control?

Mike Phelan · 4th Jan 2006, 9:11 am

My Blaupunkt uses the VHF tuning for bandspread SW.
Is your distortion only on FM?

grizzy68 · 4th Jan 2006, 3:18 pm

Yes, it appears to be a volume control problem. The volume will not turn all the way off and when I turn the volume to about 25% it sounds ok and anything after that it is if it has too much base or there is destortion on the FM. SW/Am sounds better, but I think it is due lack of base. I hooked up good external speakers and I had the same problems.

2nd Jan 2006, 7:37 am	#1
grizzy68 Retired Dormant Member Join Date: Dec 2005 Location: Bel Air, Maryland, USA Posts: 20	Strange telefunken shortwave problem HELP!!!!! Hello, I am having some really wierd things happing with my telefunken opus 7. I hooked up an antenna to the shortwave and found that I get a lot of stations around the world, but there is a dial for sw/am and a dial for fm. When I find a sw station and I turn the fm dial it affects the tuning on shortwave for better or worse. Why is this happing? I also notice the sound is better on sw, less destortion. When I tune in a fm station I can get it in clear, but there is destortion when I turn up the volume. Is there a relationship to the two bands? Thanks David

2nd Jan 2006, 10:53 am	#2
ukcol Rest in Peace Join Date: May 2003 Location: Harlaxton, Lincolnshire, UK. Posts: 3,944	Re: Strange telefunken shortwave problem HELP!!!!! With regard to the first effect you mention, this is probably normal. I don't know the Opus 7 but I would be prepared to bet that the FM tuning is used to provide a band-spread function on SW. That is, you carry out a course tune to the required SW station with the SW tuning knob and scale and then fine tune using the band-spread function provided by the FM tuning scale and knob. If you look closely at the FM scale there is probably an additional scale besides the normal VHF one. The distortion on FM is probably a quite separate problem.

4th Jan 2006, 4:25 am	#3
grizzy68 Retired Dormant Member Join Date: Dec 2005 Location: Bel Air, Maryland, USA Posts: 20	Re: Strange telefunken shortwave problem HELP!!!!! What do you think is causing the destortion in the fm & volume control?

4th Jan 2006, 9:11 am	#4
Mike Phelan Dekatron Join Date: Nov 2003 Location: Near Leeds, West Yorkshire, UK Posts: 4,609	Re: Strange telefunken shortwave problem HELP!!!!! My Blaupunkt uses the VHF tuning for bandspread SW. Is your distortion only on FM? __________________ Mike.

4th Jan 2006, 3:18 pm	#5
grizzy68 Retired Dormant Member Join Date: Dec 2005 Location: Bel Air, Maryland, USA Posts: 20	Re: Strange telefunken shortwave problem HELP!!!!! Yes, it appears to be a volume control problem. The volume will not turn all the way off and when I turn the volume to about 25% it sounds ok and anything after that it is if it has too much base or there is destortion on the FM. SW/Am sounds better, but I think it is due lack of base. I hooked up good external speakers and I had the same problems.