R71a Exhibiting New Trouble

[ridgescan]

[FONT=&quot]Had the R71a going tonight and after about 2 hours, it started popping in/out of 'signal'. IOW full reception of a signal would suddenly be lost, the 'signal' indicator would go out, and the S-meter would set right at s7-then it would pop back normal...and repeat randomly. Any signal in SW, MW, strong but moreso in weaker signals, Slight flux in lights with it. Anyone have these symptoms? What do I have now?[/FONT]
[FONT=&quot]Would this have anything to do with the volatile memory battery I never changed out? Display normal.
[/FONT]​

 

[ridgescan]

Excuse me. Now it's full-on no-go. Turned it on to make a clip of its behavior and now the S-meter sets at s7 and signal's out.
Already told my gal I may be buying an R8600 but $2500 stings my hip pocket.

 

[ve3ext]

r71a

is it dead in all frequency ranges.
let us know this much??
jerry ve3ext

 

[ridgescan]

is it dead in all frequency ranges.
let us know this much??
jerry ve3ext

Yes Sir Jerry, here's a clip.
https://www.youtube.com/watch?v=oNzWi53gGUU&feature=youtu.be

 

[RFI-EMI-GUY]

Yes Sir Jerry, here's a clip.
https://www.youtube.com/watch?v=oNzWi53gGUU&feature=youtu.be

Well I can't see the video because apparently it uses a CODEC that is too new for me.

I would check

1) Power supply voltage and ripple. The power supply should produce 13.5 VDC or so with the radio on. If you pull the red jumper in the back, the supply will rise to 18 or 19 VDC by design. Don't do this and then slam the jumper back in or you will blow the meter lamp and possible more.

2) If the S meter is at some arbitrary value, it could be the S meter squelch. When you turn the squelch above a certain level it shifts to a mode where it squelches all below that S meter value. A very normal action. If the squelch is fully CCW, then you m ight have a squelch or AGC fault.

3) The R71A has a memory battery on a plug in RAM board. It is a rectangular board. The soldered in lithium battery contains the radio firmware. Unless you have some odd stuff in the VFO display or memory, it is probably OK. It has a BR2032 battery which is special lithium concoction and still available from Digikey. However changing it requires applying 5V to the memory chips. God forbid you lose 5V or short to ground while soldering.

Use a 3 X AA battery holder to apply the 5V and make sure it is floating from ground. A company called PIEXX can provide a replacement RAM board for a fairly low price. Buy a new RAM board if you must, it is a good investment unless the radio is pretty nasty.

I once bought a "defective" R71A and it turned out the owner had set the squelch, the RF gain and other controls in totally bassakward modes from normal. It worked fine and was quite impressive to the seller who I had forked over $175 in 1988 dollars for a then $450 radio. The operators manual shows all normal conditions clearly.

The R71A is a very WORTHY radio to repair.

 

[ridgescan]

Well I can't see the video because apparently it uses a CODEC that is too new for me.

I would check

1) Power supply voltage and ripple. The power supply should produce 13.5 VDC or so with the radio on. If you pull the red jumper in the back, the supply will rise to 18 or 19 VDC by design. Don't do this and then slam the jumper back in or you will blow the meter lamp and possible more.

2) If the S meter is at some arbitrary value, it could be the S meter squelch. When you turn the squelch above a certain level it shifts to a mode where it squelches all below that S meter value. A very normal action. If the squelch is fully CCW, then you m ight have a squelch or AGC fault.

3) The R71A has a memory battery on a plug in RAM board. It is a rectangular board. The soldered in lithium battery contains the radio firmware. Unless you have some odd stuff in the VFO display or memory, it is probably OK. It has a BR2032 battery which is special lithium concoction and still available from Digikey. However changing it requires applying 5V to the memory chips. God forbid you lose 5V or short to ground while soldering.

Use a 3 X AA battery holder to apply the 5V and make sure it is floating from ground. A company called PIEXX can provide a replacement RAM board for a fairly low price. Buy a new RAM board if you must, it is a good investment unless the radio is pretty nasty.

I once bought a "defective" R71A and it turned out the owner had set the squelch, the RF gain and other controls in totally bassakward modes from normal. It worked fine and was quite impressive to the seller who I had forked over $175 in 1988 dollars for a then $450 radio. The operators manual shows all normal conditions clearly.

The R71A is a very WORTHY radio to repair.

Thanks for the fast reply. Sorry about the video-it's there. I'm likely going to buy an R8600 to replace my beautiful R71A at the desk. The R71A will then go to the closet to be repaired someday I remember there was a guy who did this particular rig-repairs, tune-ups etc. but this was about 7 years ago. If anyone knows of that guy, pleas let me know

 

[RFI-EMI-GUY]

Thanks for the fast reply. Sorry about the video-it's there. I'm likely going to buy an R8600 to replace my beautiful R71A at the desk. The R71A will then go to the closet to be repaired someday I remember there was a guy who did this particular rig-repairs, tune-ups etc. but this was about 7 years ago. If anyone knows of that guy, pleas let me know

I am watching the video now. Is the "NOTCH" filter button pressed in? Stop that!

 

[RFI-EMI-GUY]

Also check the RF gain control. I ascribed operation of the squelch control to the meter, but in fact the RF gain control as adjusted to lower the gain will cause the meter to rise.

I would look at the manual and set all the controls as described for normal operation. Then exercise each one to burn through corrosion and dusty that may be causing a potentiometer or switch to malfunction.

The lack of signal indicator lamp indicates a fault or missetting on RF gain or Squelch.

Has anyone been in your shack fiddling with the radios? Kids, GF, Maid? I would blame a cat, but usually they can only mess with the VFO knob.

I don't think an RF stage is out or you would hear nothing. Audio being low, points to AGC or RF gain.

You can fix this with some fiddling or contact cleaner.

 

[ridgescan]

It's not the settings. Naturally I went through a check on all of them when this started last night as a random cut-off. It's manifested itself into a permanent outage since. All settings are as they always were utilized by me. Now, with this problem, AF gain, squelch, and even the PRE/OFF/ATT control are suspended. I've been operating my R71A EVERY single day, several hours a day, since I got it in 2009. I am well-aquainted with every nuance of its operation. Why shouldn't I utilize notch? It's effective in SSB as well as AM in MW. It's an internal problem.

 

[RFI-EMI-GUY]

Probably the RF Gain or AGC loop. Those all have various controls and just like you might have a noisy volume knob, the RF gain or Squelch pots and switches can get flaky. Exercising them might help. The panic over the Notch is that if Notch control is centered and the button pushed in it sucks all the gain out of the IF stage - been there done that.

Still you should check for 13.5V DC at the red jumper on the back.

 

[ridgescan]

Probably the RF Gain or AGC loop. Those all have various controls and just like you might have a noisy volume knob, the RF gain or Squelch pots and switches can get flaky. Exercising them might help. The panic over the Notch is that if Notch control is centered and the button pushed in it sucks all the gain out of the IF stage - been there done that.

Still you should check for 13.5V DC at the red jumper on the back.

Oh you SON OF A GUN, RFI-EMI-GUY! So I read your post and I go "gees OK I'll exercise the damn RFgain again...and the squelch-what the hell". Well guess what? You SON OF A GUN!
https://youtu.be/1czrlzHMvv4
No-it's out again and more working of the controls is not working. But it WAS back for a minute.

 

[RFI-EMI-GUY]

Oh you SON OF A GUN, RFI-EMI-GUY! So I read your post and I go "gees OK I'll exercise the damn RFgain again...and the squelch-what the hell". Well guess what? You SON OF A GUN!
https://youtu.be/1czrlzHMvv4
No-it's out again and more working of the controls is not working. But it WAS back for a minute.

If you can find a radio shack store still in business you can get a can of spray for tuners and volume controls. Take the covers off and squirt some in. Those are ganged controls so you have to get they spray in all the right places. There could be cold solder on the terminals as well. But in any event your are close.

Those radios are bullet proof. The RF gain being the least used knob on the radio is probably oxidized.

Buy the fancy new radio if you must, but the thought of that R71A languishing in a closet is too much!

 

[RFI-EMI-GUY]

CAIG LABS PRO GOLD spray A++ comes recommended for cleaning controls.

 

[ridgescan]

Thanks buddy-you've been a big help! I already have a new can of Caig DeOxit D5 here and half a can of Deoxit Gold. I am going to do some cleaning like you said as soon as I can. I hope this was it! But still wanna get the 8600 I have two HF antennas here and run 4 HF receivers (3 now with the sick 71A), but there's an extra post doing nothing on the Alpha Delta-4 to the Wellbrook so...

 

[RFI-EMI-GUY]

I have been looking at the R8600 for I/Q capabilities. I have an IC-R9000 that of course is a great beast. I like the big knobs, display and buttons. I could add an SDR off of the IF tap, but there are some limitations in doing that. I would like to have a waterfall display and some digital mode analysis.

In my opinion ICOM is at the top for good commercial grade receivers.

Sherwood Engineering has tested a bunch of receivers over the years including the R8600

Receiver Test Data

Keep me posted on your fix and how you like the new radio.

 

[ridgescan]

I have been looking at the R8600 for I/Q capabilities. I have an IC-R9000 that of course is a great beast. I like the big knobs, display and buttons. I could add an SDR off of the IF tap, but there are some limitations in doing that. I would like to have a waterfall display and some digital mode analysis.

In my opinion ICOM is at the top for good commercial grade receivers.

Sherwood Engineering has tested a bunch of receivers over the years including the R8600

Receiver Test Data

Keep me posted on your fix and how you like the new radio.

Thanks will-do.

 

[dave524]

If you have lost the volatile ram memory from a dead battery , it is gone, replacing the battery will not bring it back. There are some options at that point though

ICOM RamBoard

https://www.piexx.com/?main_page=product_info&products_id=26

WILLCO ELECTRONICS NO-FAIL MEMORY FOR ICOM RADIOS

 

[ridgescan]

If you have lost the volatile ram memory from a dead battery , it is gone, replacing the battery will not bring it back. There are some options at that point though

ICOM RamBoard

https://www.piexx.com/?main_page=product_info&products_id=26

WILLCO ELECTRONICS NO-FAIL MEMORY FOR ICOM RADIOS

Thanks for info and links

 

[R7000]

Go in and unplug all the board connectors and plug them all back in. There are dozens of them. This is what Icom told me to do before sending anything back to them.

Tom

 

[ka3jjz]

That first link Ridge gave uses a lithium button battery that is good for 7 years. After that, it kinda sounds like you're right back where you started from

Be cautious...Mike