I have a question and wanted any advice i can get I recently picked up a Uniden Washington looks in great shape, this radio has to 4 pin Mic connection for some reason I was thinking most uniden washingtons had 5 pin was there both 4 and 5 pin made ? I've had good reports working am channels with this radio but sideband seems to be hard for people to get me tuned in I have too have my clarifier all the way counter clock wise to hear others,I have done some utube research and seems mine isn't unlocked. I also noticed it looks like a capacitor connecting pin 2 on the mike jack is not connected looks to me like this goes to the phone input ? any advice ?
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Uniden President Washington
- Thread starter NY 38
- Start date
https://www.qsl.net/kf6foz/transitional/transitional.html sounds like that is a hacked up radio
The old Washington, with the UPD858 PLL, is a 4 pin. Sounds like alignment is needed and possibly clarifier unlock. If there are 2 buttons lower right side, it is the 858, if it has 3, it is a later model with MB8719 and shoud have 5 pin mic connector. Anther telltale, is if the radio was made in Japan, it is 858. Taiwan or other, 8719.
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ok well I have both my first Washington was the original President made in Japan with the 858 2 button, The one I recently bought is the Uniden Washington 3 button made in Philippines ! both radios have 4 pin mic plug this Uniden sure don't look like it's been hacked up
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Nope. The 1978 "President" brand Washington came with a 4-pin mike socket and a relay inside. Had the uPD858 PLL in it.
Later "Uniden" Washington after 1979 had a 5-pin mike and *NO* relay inside. This radio had the MB8719 PLL chip. The extra pin provides a second ground circuit. It was added as a way to get rid of that pesky relay. Pin 2 is ground for the mike audio's shield only. Pin 4 is ground for the transmit/receive switching *only*.
When they were new, people wanted to use their 4-wire mikes with this radio and had to confront an arithmetic problem. Four doesn't equal five. You can do one of three things.
Connect your only ground in the four-wire cord to pin 2. Tends to squeal on receive.
Connect it to pin 4. Tends to squeal more on transmit.
Tie a jumper wire across 2 and 4, then connect to that. This will tend to share the squeal goodness between transmit and receive.
People will install a 4-pin socket in a 5-pin radio out of frustration, wanting the radio to be compatible with mikes that get used on other equipment. Inside the radio you will find someone has used one of the three math solutions above inside the radio, rather than doing it inside the mike plug.
We used a relay to keep the pin 4 ground separate in these radios. Customers who wanted their 5-tone beeps in this model had a problem. No relay on that board. No way to shut off the speaker while the beep is playing. Adding a relay inside the radio would do this and allow putting a 4-pin socket on the radio. You're only using three pins when that relay gets installed. No need to retain a five-pin socket just to use three pins. Just one problem. The relay would activate the speaker a fraction of a second faster than your thumb releasing a PTT button. This resulted in a "POP!" from the speaker when you unkey. Kinda annoying. We developed an adapter board soldered to the rear of a 4-pin socket that had two relays. One that would unkey the transmit, and a second relay that would hesitate a twentieth of a second before activating the speaker. This fixed the "POP!" problem, but the tiny, tiny relays we used were not up to the job. The audio current in the receive speaker would wear out the relay's contact points, making the receiver audio come and go. Every relay we could buy with enough current rating just wouldn't fit behind a mike socket and still fit inside the radio.
Bummer.
Never did come up with a redesign that we could rely on.
And if your radio works like it should with a 4-pin mike socket, count your blessings. Some folks get away with it, some don't.
73
Later "Uniden" Washington after 1979 had a 5-pin mike and *NO* relay inside. This radio had the MB8719 PLL chip. The extra pin provides a second ground circuit. It was added as a way to get rid of that pesky relay. Pin 2 is ground for the mike audio's shield only. Pin 4 is ground for the transmit/receive switching *only*.
When they were new, people wanted to use their 4-wire mikes with this radio and had to confront an arithmetic problem. Four doesn't equal five. You can do one of three things.
Connect your only ground in the four-wire cord to pin 2. Tends to squeal on receive.
Connect it to pin 4. Tends to squeal more on transmit.
Tie a jumper wire across 2 and 4, then connect to that. This will tend to share the squeal goodness between transmit and receive.
People will install a 4-pin socket in a 5-pin radio out of frustration, wanting the radio to be compatible with mikes that get used on other equipment. Inside the radio you will find someone has used one of the three math solutions above inside the radio, rather than doing it inside the mike plug.
We used a relay to keep the pin 4 ground separate in these radios. Customers who wanted their 5-tone beeps in this model had a problem. No relay on that board. No way to shut off the speaker while the beep is playing. Adding a relay inside the radio would do this and allow putting a 4-pin socket on the radio. You're only using three pins when that relay gets installed. No need to retain a five-pin socket just to use three pins. Just one problem. The relay would activate the speaker a fraction of a second faster than your thumb releasing a PTT button. This resulted in a "POP!" from the speaker when you unkey. Kinda annoying. We developed an adapter board soldered to the rear of a 4-pin socket that had two relays. One that would unkey the transmit, and a second relay that would hesitate a twentieth of a second before activating the speaker. This fixed the "POP!" problem, but the tiny, tiny relays we used were not up to the job. The audio current in the receive speaker would wear out the relay's contact points, making the receiver audio come and go. Every relay we could buy with enough current rating just wouldn't fit behind a mike socket and still fit inside the radio.
Bummer.
Never did come up with a redesign that we could rely on.
And if your radio works like it should with a 4-pin mike socket, count your blessings. Some folks get away with it, some don't.
73
This is interesting stuff. The Uniden Washington I am working on has the 4 pin mic, no relay and the 8719 PLL. However, I doubt it came that way with all the other "mods" I am finding in it.
This thing worked great before I had the clarifier issue, so I never really looked inside other than shortening the extra channel wires to try to fix the freq jumping. The clarifier issue was a bad CT3 (CT2 and CT1 also going bad), but got them close enough to use. The power supply was cranked up to 18v, the harmonic filter coils were spread out, VR6 is stuck out the back, and the clarifier was opened up with a useless 20kHz of swing. Readjusting the PS to 13.8v and readjusting the bias current, AM, which I never use, looks like crap unless the pot is set just right on the back, and even then, its peaking at about 4v. I stopped last night after getting sideband ok enough to talk on, but still low power (20v pk into 50Ω so 4w on SSB). I squeezed the coils back together and now the harmonics are down about 60dB with very little spurious emissions and the finals didn't exceed room temperature. Cool part was I was able to hold a conversation with a guy 74 miles away all night with that 4w on SSB! Great conditions locally! The warmest part was the bridge rectifier in the PS!
Heres the problem, and maybe someone here knows because I wasn't smart enough to check before changing stuff. Is cranking the PS voltage part of some fancy swing mod for this radio? After seeing what all was changed inside, some of which I would never consider doing myself, the radio received nothing but good reports of big clean audio. Not sure why the harmonic filter was touched as squeezing them back together did nothing to the 27MHz, just lowered the harmonics, but obviously something that was done did seem to help. Just not sure what it was.
An interesting discovery was that after lowering the supply voltage, I would get a squeal in the RX audio when the volume was turned up. Doing the alignment on the cans seemed to clear that up (Lou's book did mention IF adjustments can cause that, but I still don't understand it). I have a long way to go on this radio now, and I am unsure whether I want to go all-stock or try to figure out what the last guy did to it. I must admit, butchery aside, the audio did sound good the way it was set before, so maybe with the harmonic filter doing its job, this higher-voltage mod is worth learning... I don't know.
Edit: surprised the audio IC didn't go with that much PS voltage!
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Can't speak to all the issues presented here, but I'll tell you what little I do know.
Spreading the coils was a trick to get wattmeters to show higher output. The meter doesn't care what frequency those watts are on so harmonics get measured right along with your fundamental. A nickname for the guys who spread the coils to get that higher reading is "meter beater."
The higher voltage trick wasn't so much a swing mod as an attempt to squeeze more watts out overall. The problem with this is that it will make your silicon bits run hotter. It may also exceed the voltage rating on some of your capacitors. They'll hold on as long as they can, but if you're hitting a 16 volt cap with 18 volts eventually something will give. You'd have to check your radio to see if the caps have been upgraded to higher voltage units.
Can't answer the rest. I'm not a radio repair professional, nor do I play one on TV.
Spreading the coils was a trick to get wattmeters to show higher output. The meter doesn't care what frequency those watts are on so harmonics get measured right along with your fundamental. A nickname for the guys who spread the coils to get that higher reading is "meter beater."
The higher voltage trick wasn't so much a swing mod as an attempt to squeeze more watts out overall. The problem with this is that it will make your silicon bits run hotter. It may also exceed the voltage rating on some of your capacitors. They'll hold on as long as they can, but if you're hitting a 16 volt cap with 18 volts eventually something will give. You'd have to check your radio to see if the caps have been upgraded to higher voltage units.
Can't answer the rest. I'm not a radio repair professional, nor do I play one on TV.