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Help with 858 Washington

I just checked and I was not able to locate an extra L37. However, I do have a friend that has a couple parts radios, he may have an extra D858 board laying around somewhere. I will check with him and report back when I can.


~Cheers~

How awesome is that, man. I don't know what to say other than a big "thank you".

Update 1: USB, channel 19, ALC 180 degrees out, mic gain down, carrier balance adjusted to null out needle...
Lowest bias reading I can get is around 75-80 mA...
One thing I noticed is that it's difficult to null out the needle absolutely on the radio with the carrier balance. With my reading glasses on, I noticed that the needle was not quite all the way over before. About the only thing that works is dialing down L39, (in conjunction with fiddling with VR4), which drops SSB output significantly.
When I get it so that the needle stays ALMOST at ABSOLUTE "zero" on SSB keyup, I can only get 5w avg on SSB and AM, but I get lower amperage readings when biasing the final...perhaps I am getting some stray signal over at the final which may be causing me to be biasing it too low, because that 70 mA reading may actually be something far lower, which may be contributing to this low output issue...?
I know if I was a competent tech who was familiar with this radio this would be 1-2-3.

Quick note- biasing the 2166 driver was a snap; checks out at 40 mA from the minute I
dropped it in and biased it the first time.

I will check out continuity on L37 and update soon.
 
How awesome is that, man. I don't know what to say other than a big "thank you".

Update 1: USB, channel 19, ALC 180 degrees out, mic gain down, carrier balance adjusted to null out needle...
Lowest bias reading I can get is around 75-80 mA...
One thing I noticed is that it's difficult to null out the needle absolutely on the radio with the carrier balance. With my reading glasses on, I noticed that the needle was not quite all the way over before. About the only thing that works is dialing down L39, (in conjunction with fiddling with VR4), which drops SSB output significantly.
When I get it so that the needle stays ALMOST at ABSOLUTE "zero" on SSB keyup, I can only get 5w avg on SSB and AM, but I get lower amperage readings when biasing the final...perhaps I am getting some stray signal over at the final which may be causing me to be biasing it too low, because that 70 mA reading may actually be something far lower, which may be contributing to this low output issue...?
I know if I was a competent tech who was familiar with this radio this would be 1-2-3.

Quick note- biasing the 2166 driver was a snap; checks out at 40 mA from the minute I
dropped it in and biased it the first time.

I will check out continuity on L37 and update soon.
Don't think you could do much better nulling the carrier than you have. However, you might try a Cermet multi- turn VR of the same resistance value, since this will help - albeit just a little. Never really have been able to get it down to zero - even with one of those special VRs.

Dunno if someone gave you this link yet; but here it is:
http://unit399.wixsite.com/858ssb
 
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Misfit,

Do this for me when you can. Remove all the jumpers on the "hacked up" side of L37, and check continuity between the 3 posts. Check bottom leg to middle leg, middle leg to top leg, and then check bottom leg to top leg. These should all show continuity on a multimeter. If any of these do not check, then L37 is bad and has to be replaced. I'm with Kopcicle on this one, there is a possibility that L37 has gone open for whatever reason, and the 82pF cap across it is "completing the circuit". I don't have hardly any radios anymore for parts, but I can check to see if I have an extra L37 laying around... if I have one, I can send it to you.

~Cheers~
Ok, Update 2: Continuity between bottom leg to middle leg, middle leg to top leg, and bottom leg to top leg, when desoldered from circuit on the hacked up side.
Stumped.
 
Here's a pic of an unmodded L37 if this helps.

[photo=medium]5055[/photo]

Now if you try to "unmod" it again, you'll need to really turn on those slugs quite a bit to get it to where it shows output. You'll want to do this in AM mode, both slugs will be approximately 2-3 full turns from being flush with the top of the can. Use that as a starting point. If you're getting continuity on all 3 legs, you should get output if it's "redone" back to stock, and the slugs have been turned to the positions stated above.

Also, to get the final bias down further, replace the trimmer pot at VR16 with a 1k (it'll be labeled 102 on the pot itself). That will allow you to get the bias current down to where you need it.


~Cheers~
 
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Here's a pic of an unmodded L37 if this helps.

[photo=medium]5055[/photo]

Now if you try to "unmod" it again, you'll need to really turn on those slugs quite a bit to get it to where it shows output. You'll want to do this in AM mode, both slugs will be approximately 2-3 full turns from being flush with the top of the can. Use that as a starting point. If you're getting continuity on all 3 legs, you should get output if it's "redone" back to stock, and the slugs have been turned to the positions stated above.
This was the priceless information and direction my feeble brain needed. Thank you exit13! I cannot thank you enough. This whole ordeal was caused by my inexperience and impatience!

WOW.
Just, wow.
I had "unbroadbanded" it maybe 3 times before and had no output. This time, after looking at the meter showing zero, I hung in there to try and adjust it like you suggested and after almost giving up, I finally saw a blip of needle movement after furiously turning L37 and L39...(VERY sensitive!) After some coil tuning, SSB immediately popped up to 15 watts AVG! I set AM dead key at 2 watts; modulates to 8 watts AVG, 15 watts PEP!
(This is with limiter and ALC circuits intact.)
Also, to get the final bias down further, replace the trimmer pot at VR16 with a 1k (it'll be labeled 102 on the pot itself). That will allow you to get the bias current down to where you need it.


~Cheers~
After changing VR16 to 1k, I am now at 25mA driver, 50mA final, as you suggested.
Should I keep it here? Is it safe? I realize the factory manual suggests 40 mA and 15mA..
 
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Exitthirteen I like the quality of the picture your camera takes. I did not have a digital camera until a few weeks ago and the one I bought has fair picture quality but yours works very good. what camera did you use to take that picture?
 
So, what have I learned?
To be patient, LOL.
My initial thought that L37 was a big part of the problem was on track, but I lacked the knowledge, experience and therefore, the confidence to "just fix it". I am sure if any of you guys had the radio in front of you, it would have been a quick fix, followed by a 10 minute alignment to get here.
For me, it took a month of pestering you guys and hair pulling, but after all this and being fresh in my mind I am ready to try another one! Thanks again, Robb, Nomad, oldtech, Kopcicle, and exitThirteen. Last but not least, the patience and kindness of 399 who put up with all my annoying emails and who "wrote the book on the 858"!
So, after all is said and done, this radio has had the following work recommended by 399 and others:
Changed out the 2 x ECG236's (one driver, one final) for a 2SC2166 driving a 2SC1969. (Thanks nomad and 399 for this suggestion)
Also Changed out:
VR15, VR16, VR7 and VR8
Replaced all tantalums with same values, but 25v (except c140 and c141 are still original)
AM regulator (2SC1419) replaced with a GE-66
TR35 VCO (Listed on the schematic as a 2SC945, BUT was actually an outhouse 2SC458; replaced with a 2SC945).
Replaced all electrolytics with values according to the TRC449 schematic (all 10v upgraded to 25v, all 16v upgraded to at least 25v) - I didn't just grab caps and replace according to what was there, because more than a few were different values from what was listed on the schematic.
Upgraded C304 to a 10,000uf/50volt computer grade electrolytic.
Upgraded C107 to 3300uf/35v.
Upgraded C102 to 1000uf/35volts.
Restored D23, and D47-(both were clipped).
D46 was intact.
Changed D53 (on a hunch- unnecessary)
Set DC output to 14.5VDC
Replaced D10,11,15,and 16 with 1N6263 schottky diodes.
Bridged buss wire across capacitors C202, 203, 220, 221, 222, 223, and 239
Also did these exitThirteen recommended mods:
Changed R72 to 1k
Lifted the banded end of D46 and installed a 220 ohm 1/4 watt resistor in series on the banded side (cathode) of D46.

L37 coil restored to factory connection points.- Along with completely re-capping the electrolytics, upgrading and biasing the final and driver, this is what put it over the edge, as everyone suspected.
I also changed out the meter bulb with 4 LEDs, which I hot glued on from the rear after grinding them down on a hobby belt sander; 2 Green, behind the green "RF PWR SIGNAL" portion, 1 Red behind the "strawberry patch" and 1 white behind the "S/RF PWR" on the bottom. It looks really tricked out; colors are deep and vivid.

The formerly lazy needle is now thrashing like George Corpsegrinder Fisher and bending under my heavy-handed key downs!
But seriously, it sounds amazing and is performing beyond what I wanted out of it.
Thanks again to everyone in this thread for their patience. kindness and guidance.
 
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Glad you got it going, Misfit!!

With L37, patience is indeed your best friend when lining it up. It's very sensitive, and that's why I tried to give you a baseline starting point. You have to tune one "half", then the other "half", then back to the first one again, then back to the second one, and you have to go back and forth a few times to get it dialed in just right.


Since you are using the C2166/C1969 pair for the driver/final, 25mA/50mA are what I recommend. These settings will not harm the transistors, and will produce very clean output in all modes. If you would have had the original C1306/C1307 pair in there, then you would want to use the 40mA/15mA bias settings.


Sonoma, I took that picture with an iPhone 6 Plus, since you were curious. :)

~Cheers~
 

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