RX issue on Midland 2001 UKFM

[The Collector]

Hey all.

As I've mentioned previously on a couple of posts, I have a little Midland that decided to lose its RX, it sort of just faded away over the course of about 5 minutes whilst listening to stations at a car boot sale I was doing (I was showing the receive on my old A99 aerial).

It will pick up a handheld TX'ing right next to it, but nothing normally and the normal white noise background hiss seems very muted.

I've taken a few photos of the board in the hope that someone might be able to add a little arrow to show me the likely culprit/s, whether it be a capacitor or a resistor etc.

Fingers crossed the pictures work as I'm useless with phones, co puters, app's etc and they all hate me back!:


https://david-reynolds.smugmug.com/Radio-Pics


Edit- bloody hell, the link to the pictures actually works. Normally it refuses to accept my hotmail.com email address for a start.

[wa10]

The cfw455 IF filter ( oblong black box next to the 3357 FM chip far right 3rd pic ) looks like its half out of the board but it could be the angle of the pic making it look like that.

[ChubbyChops]

I'd start with C142 and the cap next to it.

[The Collector]

Thanks chaps, I'll have a look at those tomorrow

Hopefully I can find C142, as I may as well be playing "Battleships" inside with my knowledge. If it looked like a flashing Flux Capacitor from a certain film, then it'd help matters Luckily, there aren't that many capacitors.

I'd like to at least have a quick go at it myself before it gets sent off for repair.

[14CS06]

Hello

C 142 in front of IC 104

@+
Claude

[The Collector]

Thanks Claude, I've managed to find it on your attached schematic..that'll come in handy by the way.

I haven't had a chance to look at it today as I've been refurbing our barbeque in readiness for some use (hopefully) soon.

[The Collector]

Well I took pictures of the 3 capacitors in that area and I ordered a box of 500 assorted capacitors from ebay last night. I'll just replace them one at a time and see if it makes a difference. I'll then move further along a bit if I have no joy...so long as I've got the right values as some look quite large.

Regarding the rectangular block filter thing wa10, although it's been soldered in at a little bit of an angle, it looks okay and the solder tabs all look good on the other side if the board. I can aways give them a quick remelt when I've got the soldering iron going, just in case. Good spot though!

[ch25]

What is the voltage on input and output of 455kHz filter when radio become deaf?
Measured against electrical ground ofc.

[The Collector]

What is the voltage on input and output of 455kHz filter when radio become deaf?
Measured against electrical ground ofc.

Chris - I appreciate your help/input, but you have to understand that you are trying to ask questions that a Neanderthal/buffoon/idiot like me would probably not understand If someone points to something and says "Change that", then that I can probably do. However, if someone says "Check the voltage or impedance at the collector's positive relay differential coilymijig", then I'd simply scratch my head and switch off my phone, all confused

I'll try the capacitors first and if that fails, then perhaps I'll try and risk something more daring. Capacitors have only got 2 legs and as long as I put the stripe the right way and don't spread solder all over the board, then hopefully I can succeed! If it's going to cost more than a couple of quid for a component that confuses me, it's going to end up in a box and sent to Nick, Black Spirit.

Spray painting, drilling, filling and relettering radios I was capable of...fixing electrical component stuff is another matter.

Cheers mate.

[ch25]

Replacing components without measuring and diagnose is like playing roulette. Eventually you'll find. Maybe it will be last part you replace all parts in that radio.

[Werthers]

I'd start with the simple things first before taking things apart. Make sure there is nothing interfering with the RX.

You need to download the service manual for that radio and start by checking the voltages around the board. Maybe some electrolytic capacitors have gone bad. You need some other test equipment to realign the RX.

There is a guy in Lincolnshire who is brilliant with repairing radios. He charges 25 quid for a service and a full realignment.

[Otter]

There is a guy in Lincolnshire who is brilliant with repairing radios. He charges 25 quid for a service and a full realignment.

What is included in the service?

[The Collector]

There is a guy in Lincolnshire who is brilliant with repairing radios. He charges 25 quid for a service and a full realignment.

What is included in the service?

The radio's only worth about £15 working, hence me having a go at it. I wouldn't send it in for repair on its own, it'd have to go in with some others to make it worth the while money-wise. If it blows up then at least I tried

[Werthers]

There is a guy in Lincolnshire who is brilliant with repairing radios. He charges 25 quid for a service and a full realignment.

What is included in the service?

The radio's only worth about £15 working, hence me having a go at it. I wouldn't send it in for repair on its own, it'd have to go in with some others to make it worth the while money-wise. If it blows up then at least I tried

Basically everything. He checks everything and adjusts what needs to be done and repairs any faults. The radio may only be worth 15 quid but when it comes back from servicing it will be 100% in good working condition. If you think about it you wont find a secondhand old CB radio that is 100% so its worth it. All old CB radios could benefit from a tune up and a general check up after so many decades.

By doing it yourself without the proper test gear you wont get very far. There was a guy called Nick "Black Spirit" who also services rigs and is very good. I'm not sure if he is still about.

I've seen a few Midland 2001 UKFM CB radios going for 40 plus quid on ebay. I have one boxed mounting bracket and everything.

[The Collector]

Mine's very tidy with its original bracket and thumb-screws (can't remember if it's got its original mic' off-hand), but it wouldn't be worth paying £4 postage both ways plus £25 servicing/repairs costs as it'd wipe out all the profit from selling it. It'd make more just being sold for spares/repairs, but I'd prefer to sell it as a worker. A 50p capacitor repair might reward me with an extra tenner or more if I strike it lucky Just got to wait for them to arrive now and hopefully I can have a go at it the weekend.