Uniden Washington Modulation?

[Eastside]

Why would any radio need to be aligned? To test if it is up to specs - of course!
An old radio - like this one - is more likely to be out of tune rather than being in tune.

Use the mic that you plan to use on this radio and feed it a 1khz audio sine wave signal (you can get this online) in SSB mode. If it is a power mic; then set it about 1/2 way up.

Freesound.org - "TONE 1 kHz 44.1 16bit.wav" by klangfabrik

Even though the Dosy isn't the greatest meter for alignments, it will still work for seeing the change in output in SSB mode. Set the meter to read 'peak' and 'SSB'.

Key the mic and hold it fairly close to your computer speaker and start the sine wave signal; adjust the mic gain knob until you see about 10w on the meter then tune/peak the first coil. Then follow through with the next two coils. For the last TX coil of the four will need to be set for power balance between ch 1 and then 40 - this is done to insure that the power output is relatively equal on all channels after you peak the first three coils. Should see close to ~18w when peaked after twiddling. BTW - Let the radio rest a minute between each coil being tuned as this tuning procedure will get the finals a bit too hot and possibly fail if you don't.

Use ONLY a wooden stick or the preferred nylon tuning tool; do NOT use a jewelers screwdriver!!!
Or forget about doing this entire operation.

This isn't the preferred way to do it but if you are going to DIY at home; then this method should get it pretty close.

Do it all at your own risk!

I appreciate the help and info.

Yep....I got a set of trimmer tools...got bit once by a tube radio and that was enough to make me break down and buy a set...even though the price seemed high.

Which " cans" are you referring too?

Always understood.

 

[Eastside]

I have 3 washingtons like this that does 3 watt dead key and swings 18 to 20 on am and 25 on ssb. this is without any mods done to them. I just bought a uniden 880 and it was doing 3 watts dead key and swing to 4 watts and I just peaked it a little and now it does 3 watts dead key and 10 watts swing. the factory normally just see's that it puts out and lets it go. they do not set there and play with the tuning cans to peak it out. as long as it does 4 watts thats it.

Ha ha...your Washington poor....I always wanted 1.
Its jamming on SSB....just AM suks.....hope I can get mine to perform like yours.....it swings over 20 watts on SSB when you whistle into the mic.

 

[sonoma]

I appreciate the help and info.

Yep....I got a set of trimmer tools...got bit once by a tube radio and that was enough to make me break down and buy a set...even though the price seemed high.

Which " cans" are you referring too?

Always understood.

the service manual from defpom's sight that I sent you to has the pot location numbers and which to turn for each item.

 

[Eastside]

the service manual from defpom's sight that I sent you to has the pot location numbers and which to turn for each item.

Do you have a link to the service manual download?

These?

L26 TX mixer input
L27 TX mixer input
L28 TX mixer output (1st stage)
L29 TX (2nd stage)
L36 TX

 

[Robb]

This is for the Cobra 142GTL; which is the same radio as the 8719 PLL Uniden Washington.

Click on the image to get it larger; or download it and enlarge it . . .

 

[Eastside]

This is for the Cobra 142GTL; which is the same radio as the 8719 PLL Uniden Washington.

Click on the image to get it larger; or download it and enlarge it . . .

I am trying to check the driver and final bias and either my MM is screwy or I am doing something wrong....it gives no reading on usb with no mod?

BTW thanks for the pic of the alignment page....danke

 

[sonoma]

I am trying to check the driver and final bias and either my MM is screwy or I am doing something wrong....it gives no reading on usb with no mod?

BTW thanks for the pic of the alignment page....danke

are you sure you have the meter on miliamps, and are you keying the radio when you try to check the amps.

 

[Eastside]

are you sure you have the meter on miliamps, and are you keying the radio when you try to check the amps.

This is how I got it set up?

 

[Robb]

The POSITIVE lead of the DVM goes to the post and the NEGATIVE lead goes on the wire removed from the post. DVM should be set to mA's. Turn off any mic gain and then key the mic.

If the radio normally works in SSB mode; then you must be doing something wrong with your testing procedure . . .

 

[Eastside]

The POSITIVE lead of the DVM goes to the post and the NEGATIVE lead goes on the wire removed from the post. DVM should be set to mA's. Turn off any mic gain and then key the mic.

If the radio normally works in SSB mode; then you must be doing something wrong with your testing procedure . . .

With the mic gain turned all the way down it will do nothing in ssb....?

I changed the leads like you said....did not make any change.

 

[Robb]

You are doing something wrong. Your meter must not be working right or you have it hooked up to the wrong places. That is all that is possible if SSB works. Yes; the mic gain must be all the way down and have the radio set on either USB or LSB mode.

 

[Eastside]

You are doing something wrong. Your meter must not be working right or you have it hooked up to the wrong places. That is all that is possible if SSB works. Yes; the mic gain must be all the way down and have the radio set on either USB or LSB mode.

Its hooked up to the right places......mebbe the dmm ammeter does not work right....I have no idea?

 

[Robb]

Take a picture of where you are hooking it up . . .

This is a picture of one of the bias posts removed because this is the only picture I could find. Do NOT remove the post; just pull the wire off of the post and connect between the two points. There are two of these posts right next to each other and they are the +8v feed for the bias circuit. There are two wires that clip to these two posts; one goes over and connects at a point close to the driver bias VR and the other goes over to the final bias VR. The positive lead of the DVM goes on the post and the negative lead of the DVM goes on the wire clip.

 

[Eastside]

Take a picture of where you are hooking it up . . .

This is a picture of one of the bias posts removed because this is the only picture I could find. Do NOT remove the post; just pull the wire off of the post and connect between the two points. There are two of these posts right next to each other and they are the +8v feed for the bias circuit. There are two wires that clip to these two posts; one goes over and connects at a point close to the driver bias VR and the other goes over to the final bias VR. The positive lead of the DVM goes on the post and the negative lead of the DVM goes on the wire clip.

Yep...that is how I hooked it up.

 

[Robb]

Got to be your meter or the leads if you key the mic and you aren't seeing any current/mA's on the meter . . .

**EDIT**
Check the fuses inside your meter! The fuse protects against over-current use. The rest of the meter may function fine; but in mA mode with a blown fuse, it won't read. Been there; done that. Bet that is it!