• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

President lincoln/ hr2510 weak receive

74fordman

Member
Jan 14, 2021
13
5
13
35
So hopefully I have this in the right place but here goes. I have a lincoln that has very weak receive and when I say weak I mean about 100 yards and that's it. On am if you turn the volume all the way up you can hear vary faint static. On USB lsb cw it's a little louder and fm you have plenty of static. Like I said though if your not within 100 yards of it you can't pick any signal. I know it's not antenna or coax anything external. I've had it to a shop he wasn't too familiar with this unit and got stumped. Anyone have any idea where to start. Oh and if it makes any difference it has a chip switch in it. Thanks
 

If it's not transmit, only receive, how do you know it's "100 yards" - by S meter reading or by Volume heard?

One is the Audio Chip and associated, (PA work?) the other deals with RX and AGC - if the radio is still OEM and never been touched, well - it will need to be and thru expressively confidential documents (A.K.A) Repair order - the radio will have to undergo surgery and replace several (hundred it seems :)) electrolytic caps - all due to age and inability to filter out noise and provide pure DC. They all act like resistors and load down the circuits they're supposed to filter out noise for.

You would also experience dimming effects and higher "idle current" problems because the radio simply consumes more power thru those caps acting more like lazy resistors than doing their jobs and taking out the noise.

@Rogerbird1 - as others have suggested - is the one to really talk to about this.

Head here (Read) if you need more research...
http://cbtricks.com/radios/uniden/hr_2510/

I'll also post this here to help others understand a quirky issue about Capacitors as they age,
they simply take in more power.
Whether to boot, use, or even turning off - the suck all the power in the power supply filter caps into themselves.
Put a Ammeter on the power leads, you'll see why...
upload_2021-7-31_11-32-19.png
 
If it's not transmit, only receive, how do you know it's "100 yards" - by S meter reading or by Volume heard?

One is the Audio Chip and associated, (PA work?) the other deals with RX and AGC - if the radio is still OEM and never been touched, well - it will need to be and thru expressively confidential documents (A.K.A) Repair order - the radio will have to undergo surgery and replace several (hundred it seems :)) electrolytic caps - all due to age and inability to filter out noise and provide pure DC. They all act like resistors and load down the circuits they're supposed to filter out noise for.

You would also experience dimming effects and higher "idle current" problems because the radio simply consumes more power thru those caps acting more like lazy resistors than doing their jobs and taking out the noise.

@Rogerbird1 - as others have suggested - is the one to really talk to about this.

Head here (Read) if you need more research...
http://cbtricks.com/radios/uniden/hr_2510/

I'll also post this here to help others understand a quirky issue about Capacitors as they age,
they simply take in more power.
Whether to boot, use, or even turning off - the suck all the power in the power supply filter caps into themselves.
Put a Ammeter on the power leads, you'll see why...
View attachment 46086
It transmits fine it's the recieve thats week
 
What about PA?

We need to rule out one of two sections - both make the radio appear to have a "weak" receive.

I asked how do you know this - S-Meter or if the audio amp section are the problem.

TX doesn't use the Audio Amp - doesn't even get close.
 
  • Like
Reactions: tecnicoloco
What about PA?

We need to rule out one of two sections - both make the radio appear to have a "weak" receive.

I asked how do you know this - S-Meter or if the audio amp section are the problem.

TX doesn't use the Audio Amp - doesn't even get close.
Pa works fine. Sitting right next to my galaxy I can pick up all kinds of traffic on the galaxy president is dead silent. Get in the truck sitting in the driveway can pick up the truck radio just not very loud leave the driveway can't hear the truck anymore. Took it to a shop transmit works like it should receive dose not
 
transmit works like it should receive dose not
Ok, reason why I asked is for this answer - sorry to bother you. Thought I could make a quick suggestion but in this case, the RX for what it is - is the problem, needs far more attention.

IT would help to know the history of the radio but save that for the tech whom will be working on it. To lose a radio just out of the driveway - noting, being an audio amp problem it would have distortion nearly all the time, if falls off as the signal gets weaker and the demand of the Receiver comes into play because the speaker can't pass all the distorted sounds it simply pinches up.

This is different - RX only - PA works ok. In older radios - everything sounding distorted - that signals a recap (meaning the Electrolytic capacitors are dried out everywhere inside it) but in this instance you seem to hear fine - only close by.

Parts for it are not easily found anymore.

@Rogerbird1 has more information on where you need to take this.

Why I mention history is due to the tech being able to determine how the fault may have occurred, internal protection - thru being too close to another station running power - or a lightning strike or EMP - onto internal regulation - AGC caps that help "slow down" wildly swinging radio signals (Flutter) can go bad affecting the ability for the radio to open it's ears to hear.

IF it was a simple recap, and you are proficient at soldering - you could save a lot of $$$ by simply doing the cap replacement yourself - replace a few, power it up - still does it - back under to replace more - until you've done them all or the condition is fixed.

You posted here looking for answers - I'm trying to offer advice based upon you and your willingness to try and fix it yourself.
 
A new member today. I hope to find someone who can check my Uniden HR2510 that was unlocked many years ago. Now that I am retired I would like to know the radio is in great condition to use and to check if it was unlocked with a chipswitch. Thank you everyone for this forum.
 
So hopefully I have this in the right place but here goes. I have a lincoln that has very weak receive and when I say weak I mean about 100 yards and that's it. On am if you turn the volume all the way up you can hear vary faint static. On USB lsb cw it's a little louder and fm you have plenty of static. Like I said though if your not within 100 yards of it you can't pick any signal. I know it's not antenna or coax anything external. I've had it to a shop he wasn't too familiar with this unit and got stumped. Anyone have any idea where to start. Oh and if it makes any difference it has a chip switch in it. Thanks

As Andy said, the capacitors usually are the issues, or front end overload can kill the diode protection (D101 & D102) in the rx, or very common the first transistor goes 'deaf' (q101 2sc1674).
If it is mainly AM/FM weak receive, it is almost always the 2 caps (C41 & C159), which are 2 electrolytics in a non-polarized configuration. If either fails, rx is depleted.
If it is simply low volume, replace C95 and C97. (use 16v caps in place of the 10v caps).
Of course, if someone has been 'peakin and tunin' and the filter(FT101) has been disturbed, it will need to be aligned properly. There is a reason the MFG put 'Do Not Adjust' labels on the filters. Not an easy tune, without the proper equipment.

I hope this helps, CB tricks has great board layouts to help with component locations.

Roger (Rogerbird)
 
As Andy said, the capacitors usually are the issues, or front end overload can kill the diode protection (D101 & D102) in the rx, or very common the first transistor goes 'deaf' (q101 2sc1674).
If it is mainly AM/FM weak receive, it is almost always the 2 caps (C41 & C159), which are 2 electrolytics in a non-polarized configuration. If either fails, rx is depleted.
If it is simply low volume, replace C95 and C97. (use 16v caps in place of the 10v caps).
Of course, if someone has been 'peakin and tunin' and the filter(FT101) has been disturbed, it will need to be aligned properly. There is a reason the MFG put 'Do Not Adjust' labels on the filters. Not an easy tune, without the proper equipment.

I hope this helps, CB tricks has great board layouts to help with component locations.

Roger (Rogerbird)
i appreciate the comeback i actually had set this one to the side for a while and just came back to it last night. this thing did have work done to it. it has a chip switch in it q188 was missing and there was a resistor clipped witch i have put back.All this work was done probably about 18 years ago and it was my fathers who is past so cant really ask what all was done. with that being said i was working on recapping it yesterday not completely done but i did replace c41 & c159 and no change. ill have to get to c95 & c97 tonight. im pretty sure d101 and 102 i tested last night and they tested good but i could always replace just to be sure. Im not sure if it makes any difference but i have full volume on fm and get loads of static in am and sideband i dont really get any static i know i said before i get faint static at full volume but i didnt even notice that yesterday when messing with it
 
  • Like
Reactions: AudioShockwav
I would look at doing some simple continuity checks from the antenna's connector - to the main PCB, back along it, thru the SWR "riser card" and back even further.

IF the radio seems to TX ok, and you seem to have wattage, have you put - hooked up the radio to a regular CB antenna - and SWR shows ok, - you may have a failed part in the AM "strip" section PAST the split that the FM riser card, the one in the middle - uses.

It shares the same strip to make itself work, and splits off it's own receive detector output - but that does not mean it was never messed with - the edge connector on this card is fragile and sensitive to heating cycles, too many of them the foil trace edge connection lifts and shreds / tears off - it's copper foil - which can interrupt the flow of IF information.

So if FM works, great, but AM uses this from that card onwards - so might need some more work or worse, a cap that I know exists that if you put it in, kills AM receive - its' by the FM riser card - if it didn't have a cap in there and you put one it - it can act up like this.

So to start, look and review the FM riser card, then look beyond the card along the direction towards the Audio Amp chip (TDA1905) - and see if you might have missed something in your initial inspection. He may have been tracking down a problem in the radio and lost interest - so it was left for you to pick up his legacy and take it from here.
 
  • Like
Reactions: Rogerbird1

dxChat
Help Users
  • No one is chatting at the moment.
  • dxBot:
    Tucker442 has left the room.
  • @ BJ radionut:
    LIVE 10:00 AM EST :cool:
  • @ Charles Edwards:
    I'm looking for factory settings 1 through 59 for a AT 5555 n2 or AT500 M2 I only wrote down half the values feel like a idiot I need help will be appreciated