L
legg
Guest
I\'ve got an Emerson ( ~ Sangean) ATS803 that has started to mistune.
Example:
Basic commercial FM band tune in 99.1MHz and get intermittent
shift in recieved signal as high as 99.9, with no alteration
in displayed frequency (reads 99.1).
This gradually worsens (by frequency pull) until the 99.9MHz
signal is continuous. To get 99.1MHz signal out then I have to
tune displayed frequency to ~ 98.4MHz. This is just a notable
example - smaller shifts have been seen (AIR). I\'ve had to
retune the display downwards in increments to keep the 99.1MHz
reception.
It is physically dependent on something. With the case open,
pressure on front display can induce it, though all ribbon
cables have a fibre insulator installed to prevent pentration
of sharp component leads.
With RF board lifted, there seems no predictable or repeated
movement of anything simple that can induce it, but movements
of the entire rf board will: This can occur with RF board close
or distant. No assembly pressure on cables is required.
Tapping/wiggling cables and connectors doesn\'t aggravate or
repair it. Tapping/rotating the digital tuning assembly doesn\'t
affect the intermitency.
Finger placement/force on RF board doesn\'t change anything.
It\'s sitting on the bench open and behaving, but I can induce
problem with mech RF board movement or by reassembly at any time.
Ack.
RL
Example:
Basic commercial FM band tune in 99.1MHz and get intermittent
shift in recieved signal as high as 99.9, with no alteration
in displayed frequency (reads 99.1).
This gradually worsens (by frequency pull) until the 99.9MHz
signal is continuous. To get 99.1MHz signal out then I have to
tune displayed frequency to ~ 98.4MHz. This is just a notable
example - smaller shifts have been seen (AIR). I\'ve had to
retune the display downwards in increments to keep the 99.1MHz
reception.
It is physically dependent on something. With the case open,
pressure on front display can induce it, though all ribbon
cables have a fibre insulator installed to prevent pentration
of sharp component leads.
With RF board lifted, there seems no predictable or repeated
movement of anything simple that can induce it, but movements
of the entire rf board will: This can occur with RF board close
or distant. No assembly pressure on cables is required.
Tapping/wiggling cables and connectors doesn\'t aggravate or
repair it. Tapping/rotating the digital tuning assembly doesn\'t
affect the intermitency.
Finger placement/force on RF board doesn\'t change anything.
It\'s sitting on the bench open and behaving, but I can induce
problem with mech RF board movement or by reassembly at any time.
Ack.
RL