RCI 69 base

Handy Andy · Jul 3, 2021

Yes, because you're checking for wiring issues, make sure you didn't short Drain or Source to gate by accident

Something happened to make them fail, don't want to recreate the same problem again...

When all the Gates are set to minimum, (or left alone to float at their Gate voltage) they should NOT change when the jumpers to power their Drains (center) are applied.

It's when they do, you may have (with any type of carbon trail problem) a secondary path that gate voltage can now have a feedback path and generate a loop - another catastrophic failure can occur.

The MOSFET's are VERY sensitive to loading and if any path is given, they will take it.

Find several Bipolar radios that simply cannot take MOSFET's without a major rework and that includes cleaning off the boards to remove any old debris that Bipolars would not have reacted to as severely.

Since these are Discrete - the level of reactive paths are very high and they have not addressed the layout requirements that MOSFET's can use for better efficiency - due to the single cladding or not - the sheer level of inductive reactance is extremely high in Discrete boards due to lead lengths needed to connect the parts to the foil.

nomadradio · Jul 4, 2021

I suspect the factory turns up the gate-bias voltage above what's safe to get a bigger wattmeter reading.

Starting at zero gate Volts is the only safe way to find the desired idle current. Just gotta watch for the "kick-in" threshold where the gate begins to turn on the drain current.

The procedure in post #43 should allow setting idle current by starting with all the trimpot-controlled stages set at zero. Any current reading in transmit mode SSB, zero mike gain is your reference figure, the "zero" starting point.

73

Shadetree Mechanic · Nov 22, 2021

Just bought a new one from Anderson Radio Supply, I will be sure to check the bias.

http://www.andradsupply.com/10-meter.php

Eldorado828 · Nov 22, 2021

Shadetree Mechanic said:
Just bought a new one from Anderson Radio Supply, I will be sure to check the bias.

http://www.andradsupply.com/10-meter.php

Looks like a 69vhp inside the carcass of a galaxy 2517. Barkett was telling me that he knows of a few shops swapping out the rt1's for 520's right out of the box. He was saying the trade is lower power for longevity.

I'm still waiting to see how the rt1 works out before owning one.

Shadetree Mechanic · Nov 22, 2021

Shadetree Mechanic said:
Just bought a new one from Anderson Radio Supply, I will be sure to check the bias.

http://www.andradsupply.com/10-meter.php

They just cancelled my order because it's out of stock.......
Kind of relieved in a way, the thing is so big that I really don't have a place to put it. Then the concern for the side band audio. So it's all just as well, I might get an Icom 718.

nomadradio · Nov 24, 2021

If you plan to operate mostly sideband, that's what I would recommend.

Finally had a second one of these "69" base radios come through the shop. This one didn't sound like dirt on SSB like the first one we saw.

This seems to be the tradeoff, though. A decent sideband radio like the Icom 718 will have a compromised sound on AM transmit, but sound killer on SSB.

The "10-meter" radios frequently sound compromised on sideband, but have a dedicated AM-only modulator circuit that runs rings around the Icom's AM transmit.

Years ago I suggested someone (else) design a true AM modulation limiter retrofit for the solid-state ham HF transceivers.

Biggest compromise I see is that they don't limit AM audio in those radios. They use the sideband ALC to limit peaks. Just one problem. Touching that peak limit in AM transmit causes the carrier to get turned down along with the modulated peak power. The effect is that overmodulated AM sounds like sideband. Because it is. Turn up the mike gain enough on AM and it limits the carrier down to nearly zero.

But a true AM Modulation limiter would instead control the mike gain, and not molest the carrier level when you reach the modulation-limit level.

All I asked for was a simple drop-in mod that would take the place of the sideband ALC when you're transmitting AM.

Still waiting.

73

NZ8N · Nov 24, 2021

The Yaesu FT101 series low level modulated a separate crystal for AM transmit.
These newer Ham radios actually send AM modulation through the balanced mixer like in SSB, but add a voltage to unbalance it to impose a carrier. When the negative peaks hit, this causes the balanced modulator to produce aliasing. So, a high level 1khz tone will produce a 2khz signal, with the negative peaks and positive peaks coming through the system.

teddyboy · Jan 15, 2022

Well the year is 2022, i have bought one, what can anyone tell me about the power supply, i have heard is switchable to 240V, im hoping so as we dont use 120V, otherwise it will mean i have to get a step down converter, now if it does have a switch to make it 240V, that saves me some cash to get other things.

I have owned a 2980, and it was one of the best radios i have had

nomadradio · Jan 16, 2022

A radio sold in 2022 should have a switchmode power supply module. If it has a 120-240 switch, you're good to go.

Haven't seen one yet that doesn't have that switch.

73

Miura · Mar 27, 2022

teddyboy said:
Well the year is 2022, i have bought one, what can anyone tell me about the power supply, i have heard is switchable to 240V, im hoping so as we dont use 120V, otherwise it will mean i have to get a step down converter, now if it does have a switch to make it 240V, that saves me some cash to get other things.

I have owned a 2980, and it was one of the best radios i have had

As you probably found out by now it has a switch on the power supply inside the case but make sure to replace the fuse at the back with a 3 amp 220v

teddyboy · Mar 28, 2022

Miura said:
As you probably found out by now it has a switch on the power supply inside the case but make sure to replace the fuse at the back with a 3 amp 220v

Yes your right, it does have a switchable power supply, i was told to put 1amp fuses in, maybe this is why its blowing the fuses, i will get some 3amp fuses, with any luck that will be good, still waiting for an antenna to turn up, one it does i will be able to give you a radio report on how i found it, im getting back in after 3 yrs, its cost me a small fortune as i dont live in America but Australia, so once you convert the currency with postage and import tax its built up quiet a sum, i have had a 2980 and loved it, hope this one can match up.

Picture is my 2980...

Miura · Mar 28, 2022

teddyboy said:
Yes your right, it does have a switchable power supply, i was told to put 1amp fuses in, maybe this is why its blowing the fuses, i will get some 3amp fuses, with any luck that will be good, still waiting for an antenna to turn up, one it does i will be able to give you a radio report on how i found it, im getting back in after 3 yrs, its cost me a small fortune as i dont live in America but Australia, so once you convert the currency with postage and import tax its built up quiet a sum, i have had a 2980 and loved it, hope this one can match up.

Picture is my 2980...

Stunning radio!! Never saw one quite like yours! I agree with you a 100%! It is a very expensive hobby. No cheaper in England. After sourcing my radio(s)in the US, purchasing all the different coax, antenna, tuners, meters, pl259 plugs, lightening protector, tools, etc. it all adds up to a small fortune. I came back to the hobby after 40 years. Thank God a made a good living in between!

teddyboy · Mar 30, 2022

Miura said:
Stunning radio!! Never saw one quite like yours! I agree with you a 100%! It is a very expensive hobby. No cheaper in England. After sourcing my radio(s)in the US, purchasing all the different coax, antenna, tuners, meters, pl259 plugs, lightening protector, tools, etc. it all adds up to a small fortune. I came back to the hobby after 40 years. Thank God a made a good living in between!

The radio in the picture i lost because i trusted someone on social media, i had a few radios already and space was getting rare, so i thought i would see if i could swap it for a galaxy homebase 2547, had a couple before and they were not a bad radio, some bloke in one of the cb groups contacted me and said he had what i was after, so we exchanged pictures asked questions and settled on a swap.

When i received his radio i couldn't believe what i saw, it wasn't the one in the pictures he sent me, but one that looked like it had been kicked from one end of the street to the other. it had drill holes all over the case, its legs were broken and he screwed a piece of metal to act like a stand, the extra channels didnt work, they were on a toggle switch, i got in touch with him and told him he needs to send back my radio and i would do the same, after that he refused to reply to me, i followed him on all the cb groups and called him out on one of the groups his friend was in charge and told me not to post anything to do with this deal, i did and he blocked me from the group, then that bloke also blocked me, and that was that, nothing i could do, that was just over 3 yrs ago, so i sold up and left it, but in the last month or so i had been getting that feeling again and wanted to get another radio, after much begging to my missus she said ok, just waiting on the antenna and im up and running again.

There are No cb shops here in Australia, you can buy UHF radios but they didnt interest me, so i have to buy from ebay and pay over inflated prices for equipment, radio came from America and the antenna is coming from the Uk.

My first ever radio was a maxcom 4E, a whopping 4 watts of power, that was after the government allowed us to have cb in the uk, we were hoping to get AM and maybe sideband, well as you know they gave us FM, i still have my first brand new radio, an Amstrad 901, still works only one on to talk to on it here.

Had a lot of radios since then, even had a Cobra 2000 GTL, Originally im from Kent, we moved to Australia some years back, lots of things from back home i miss, but the cold isn't one of them..

Few More pictures to wet the appetite..

Eldorado828 · Mar 30, 2022

teddyboy said:
The radio in the picture i lost because i trusted someone on social media, i had a few radios already and space was getting rare, so i thought i would see if i could swap it for a galaxy homebase 2547, had a couple before and they were not a bad radio, some bloke in one of the cb groups contacted me and said he had what i was after, so we exchanged pictures asked questions and settled on a swap.

When i received his radio i couldn't believe what i saw, it wasn't the one in the pictures he sent me, but one that looked like it had been kicked from one end of the street to the other. it had drill holes all over the case, its legs were broken and he screwed a piece of metal to act like a stand, the extra channels didnt work, they were on a toggle switch, i got in touch with him and told him he needs to send back my radio and i would do the same, after that he refused to reply to me, i followed him on all the cb groups and called him out on one of the groups his friend was in charge and told me not to post anything to do with this deal, i did and he blocked me from the group, then that bloke also blocked me, and that was that, nothing i could do, that was just over 3 yrs ago, so i sold up and left it, but in the last month or so i had been getting that feeling again and wanted to get another radio, after much begging to my missus she said ok, just waiting on the antenna and im up and running again.

There are No cb shops here in Australia, you can buy UHF radios but they didnt interest me, so i have to buy from ebay and pay over inflated prices for equipment, radio came from America and the antenna is coming from the Uk.

My first ever radio was a maxcom 4E, a whopping 4 watts of power, that was after the government allowed us to have cb in the uk, we were hoping to get AM and maybe sideband, well as you know they gave us FM, i still have my first brand new radio, an Amstrad 901, still works only one on to talk to on it here.

Had a lot of radios since then, even had a Cobra 2000 GTL, Originally im from Kent, we moved to Australia some years back, lots of things from back home i miss, but the cold isn't one of them..

Few More pictures to wet the appetite..

Geez man, that is one sorry guy to say the least.

How does a guy like that live with that on his conscience...... Or do folks like that even have a conscience?...

Sure is a purdy station you have there!

Miura · Mar 31, 2022

Eldorado828 said:
Geez man, that is one sorry guy to say the least.

How does a guy like that live with that on his conscience...... Or do folks like that even have a conscience?...

Sure is a purdy station you have there!

teddyboy said:
The radio in the picture i lost because i trusted someone on social media, i had a few radios already and space was getting rare, so i thought i would see if i could swap it for a galaxy homebase 2547, had a couple before and they were not a bad radio, some bloke in one of the cb groups contacted me and said he had what i was after, so we exchanged pictures asked questions and settled on a swap.

When i received his radio i couldn't believe what i saw, it wasn't the one in the pictures he sent me, but one that looked like it had been kicked from one end of the street to the other. it had drill holes all over the case, its legs were broken and he screwed a piece of metal to act like a stand, the extra channels didnt work, they were on a toggle switch, i got in touch with him and told him he needs to send back my radio and i would do the same, after that he refused to reply to me, i followed him on all the cb groups and called him out on one of the groups his friend was in charge and told me not to post anything to do with this deal, i did and he blocked me from the group, then that bloke also blocked me, and that was that, nothing i could do, that was just over 3 yrs ago, so i sold up and left it, but in the last month or so i had been getting that feeling again and wanted to get another radio, after much begging to my missus she said ok, just waiting on the antenna and im up and running again.

There are No cb shops here in Australia, you can buy UHF radios but they didnt interest me, so i have to buy from ebay and pay over inflated prices for equipment, radio came from America and the antenna is coming from the Uk.

My first ever radio was a maxcom 4E, a whopping 4 watts of power, that was after the government allowed us to have cb in the uk, we were hoping to get AM and maybe sideband, well as you know they gave us FM, i still have my first brand new radio, an Amstrad 901, still works only one on to talk to on it here.

Had a lot of radios since then, even had a Cobra 2000 GTL, Originally im from Kent, we moved to Australia some years back, lots of things from back home i miss, but the cold isn't one of them..

Few More pictures to wet the appetite..

Can’t trust anyone nowaday…

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RCI 69 base

Handy Andy

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nomadradio

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