Radio problem

P

poadb

Guest
I have a Blaupunkt radio Frankfurter. FM radio works sometimes with perfect reception, and sometimes not. Other frequencies / bands have perfect reception (constantly).

1. Any, suggestion what causes the “now-and-then” FM reception?

2. Any, suggestion who can serve this type of radio (which it may be worth since the radio is in very good condition).

Regards,

Per
 
I would start with the antenna connection. FM generally demands an aerial type of antenna length for proper reception. If you have a poor or intermittent connection at the coaxial cable or the antenna mast that could be it.

I assume when you lose FM reception you still have the hissing noise of the FM tuner coming out the speaker, right? If what you hear is silence then your amplifier or speaker stages are bad (unlikely because other bands work), or some powerful FM transmitter is jamming the spectrum and "transmitting silence" (unmodulated FM).
 
Per,
Arde is right on for the antennae in addition to checking for good contact, clean both the male and female contacts at the cable ends...you may have some corrosion/oxidation leaking some of the signal.

Also, some older units (no idea brand or model, only memories) had a calibration screw for frequency.
Jon
 
blaupunkt frankfurter

i have this same radio and just had it retrofitted by s&m electrotech (several other threads about these guys), and its amazing. full orig radio functionality, plus 170 watts stereo, ipod input, etc.
if you are going to do any work on your radio you might consider this - about $400 total including shipping.
 

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Great information from all of you; I will look over cables and connections.
/Per
 
poadb said:
I have a Blaupunkt radio Frankfurter. FM radio works sometimes with perfect reception, and sometimes not. Other frequencies / bands have perfect reception (constantly).

1. Any, suggestion what causes the “now-and-then” FM reception?

2. Any, suggestion who can serve this type of radio (which it may be worth since the radio is in very good condition).
Click to expand...

I once had a similar experience with what was probably the same model Blaupunkt that was originally installed in a Mercedes. (I since pulled the radio from the car as someone damaged the surrounding console in an attempt to boost the radio. Lately I worry that the period correct dummy Pioneer has become a target.) The FM reception was excellent without extending the antenna mast. AM reception required fully extending the antenna to obtain maximum/acceptable reception. Replacement radios have uniformly required the full extension of the antenna mast to obtain the best reception. Since you are dealing with a Blaupunkt, perhaps this tale will lead you to a less-than-obvious fix. :wink:

Everything was fine until I removed and reinstalled the transmission. Afterwards, the FM radio reception for was poor and intermittent, and extending the antenna mast seemed to help, but the reception was noticeably worse than before the repairs. Having become spoiled by decent reception without extending the antenna mast, I embarked on a piecemeal quest to find out what changed.

All grounds and other connections seemed visually fine and clean. This included the antenna connections. Disassembling and re-cleaning made no change. With the car parked and the ignition off, the reception was better than with the engine running - sometimes. Discovered, by chance, that when playing with the gearshift lever, and moving my hand closer to the radio - FM radio reception improved - sometimes but not always. Reexamined the console wiring and the ignition wiring (on the other side of the firewall), but could not find anything visually wrong. Then looked under the transmission tunnel for anything that might be even indirectly affecting the radio. Discovered the reverse/backup light switch wiring was loose and left untethered to the transmission. Touching the wiring improved the radio signal. Relocating the wiring improved the signal enough so I could again listen to FM radio without the antenna mast up.

I can only guess that the car had a grounding problem and that the wiring harness and/or parts of the car body were acting as part of the antenna. Have not experienced this issue with replacement (non-Blaupunkt) radio. Can only wonder that while the radio chassis seemed properly grounded, perhaps the secondary grounding points on the dash and/or console connections were poor.

DSC007781249015830.jpg


 
Hej poadb!
Just a thought.
The antenna, is it original or a new one?

/stefan
 
It is, somewhat, new. I would guess around 1985 (a more modern radio was installed at that time).

/Per
 
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