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Fm25b Troubleshooting

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Hi all,

I am entering my fourth year of computer controlled Christmas Lights. I have been using the same Ramsey FM25B for the last three years. This year a new station started on my usual frequency. I am OK with changing the station since its not too bad but I am having trouble with static. Static is transmitted unless I put my screwdriver on the metal around the RF adjustment control. Do you guys know what can be causing this and what can be done to stop it? I think its a ground problem. I have been adjusting the potentiometers accordingly but am not getting anywhere. Also are the potentiometers supposed to be turned greater than 360 degrees. I just realized I have been doing that and I think its been causing problems.

Help would be greatly appreciated.

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Had a similar issue at Halloween with my Ramsey 25b. I was told it was likely a "cold joint" - basically something somewhere was loose. I upgraded to the Ramsey 30b. I now get reception in areas down the street that I could never hit with the 25b. Actually with the power near max, I get reception 3 miles away. I'll have to dial it down for Christmas. Worth the extra money.

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  • 11 months later...

I hesitate on the cold joint if the transmitter has been running for 3 years .. BUT .. stranger things have happened and a look over the board is NOT out of the quesiton.

However, since it worked on the freq you had it on, I would venture a guess towards the tuning ..

When you are testing the 25B a couple of things. First, here is the manual in case you lost yours http://www.ramseyele...nuals/fm25b.pdf .

Next, make sure you set the freq to 107.9 (dips at 1010 0111 1001) and look at the voltage at TP1(about 7 componets down from the antenna .. TP1 is also R21)

according to Ramsey with no input, you should be seeing around 9 volts +/- .2...

this is the important part (IMHO)... make sure you are NOT using a metal screw driver or other metal device to adjust L1.

1st is because you can break or chip the core .. and 2nd because you can change the inductance of the L1 device with the metal screwdriver making it difficult to set and stay.

Use a plastic driver for making this adjustment (radio shack if you dont have one)...

Finally tune down to 88.1 and look at TP1.. it should be .8 volts +/- .3

If everything is fine at this point and you still have the issue, then start looking at the components..There are 5 can type caps on the board. look to see if any of them have swollen or ruptured..

After that .. you still have the problem.. either find you a Ham radio guy (a REAL one .. not a paper tiger) and see if they can look over it, or .. this late in the game .. get a replacement and work the FM25 off season ..

Best I can do ...


Afterthought: No you shouldnt have to be screwing L1.. it should take only a tweak one way or the other .. I would step back and retune ...

OKAY .. MY BAD .. I was search all FM25B issues before i posted a question of my own and misread the posting date on this quesiton ... Sorry .. I'll leave it posted though.. It may help someone else down the road .. sorry about that ..

Edited by Bob Moody
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