My Second Lafayette Telsat 140 clarifier problem help

[Techno1]

So i did fix the first Telstat 140 power problem now I have a second one.
Transmits fine good audio and power both AM and ssb.

Problem is Am is dead on
USb is dead on
Lsb is not

If I transmit on AM say 27.4050 dont touch the clarifier and switch to LSB I get 27.4028 when i should get 274040 LSB is low by about .0012.
On the schematic CT-1 adjust Am and LSB and CT-2 does the USB by itself.

I replaced the 50K pot and still the same

Some where when I switch to LSB seems im loosing a small amount of voltage so that LSB will stay on frequency 27.4040. It happens on all 40 channels.
The clarifier was unlocked with same problem so i connected 1 resistor and a diode and removed the voltage wire off one side of the voice lock.
With this happening I cant realign the clarifier to center slot.

Any help appreciated
Attached is a section of the area with the clarifier and ct1 and ct 2

 

[brandon7861]

On the schematic CT-1 adjust Am and LSB and CT-2 does the USB by itself.

Typo? CT2 is LSB.

Did you set CT4?

 

[Techno1]

Brandon7861

thanks on the heads up of ct 4, I printed out the alignment page and adjusting ct-4 now has the radio spot on on Am LSB USB

thanks again for the help

 

[Techno1]

Back at the second telsat ssb140.
Seems the channel display is bad meaning some segments are out and I replaced the LED and same results.
I re-flowed all the solder joints and its definitely the wafer selector switch.

If i push on the switch some segments do come back or play with the rotary switch and kinda hold it to one side or the other segments will come back, but not all pushing on the switch, with that results i feel its the wafer contacts inside the switch are bad

Its sealed and looks like 4 parts held together by a metal bracket.
Im tempted to remove everything and try to clean the contacts.

But asking if anyone would have a parts radio to sell the channel selector.
Or if another radio would use the same selector switch?

thanks

 

[nomadradio]

It's probably built from separate plastic sections with a visible seam between them. We take the tip of a box-knife blade to separate the sections just enough for the stream from the straw on a can contact cleaner to penetrate. Doesn't take all that wide a gap to get the pressurized liquid in there.

And if it doesn't help you didn't waste much to try.

73

 

[Techno1]

It's probably built from separate plastic sections with a visible seam between them. We take the tip of a box-knife blade to separate the sections just enough for the stream from the straw on a can contact cleaner to penetrate. Doesn't take all that wide a gap to get the pressurized liquid in there.

And if it doesn't help you didn't waste much to try.

73

Nomad yes there is 3 sections with 2 sections up and 1 section down.
I took the complete assembly apart 4 times and opened each section and cleaned the wafer and all the prongs I lightly filed each one prong just to clean the tips and looked under a scope to see if any tips were bad all looked good.
The wafers also looked good i cleaned them good also.
I also slightly bent the prongs towards the wafer to put more pressure and all 3 times same results. If you lightly put pressure on the pc board some digits come back but not all.

When turning the switch some times some of the segments will be lit but stop when you let go of the channel selector.

So 3 times and cant fix as you have to de solder the 2 pc boards and then remove the bracket to get the sections out.

The radios works well just for the digital display.

So I have the word out Im looking for a parts radio or another radio that might use the same rotary switch will have to be a base radio. this is gonna be hard as these radios are far and few to be had.

 

[brandon7861]

The only thing stopping my next project from being a rotary encoder and micro for dial replacement/PLL parallel input is a non-standard encoder shaft length. Would require stocking options. It would be fairly simple to create a universal replacement with a pair of 7-seg digits.

Hopefully by winter the binaryrock will pay for bringing this idea to life too.

 

[Techno1]

Hi Brandon.

They do have the DDS modules where u replace the complete channel selector
with an encoder and module Im sure you have seen them I will have to check on a price if I cant find a good used selector for the Telsat 140

 

[Techno1]

Well I just read up on the DDS encoder module for price and install, way to much in price and way to much to install.
Price around $125.00 and i install
About 5 PDFS to read up on install and how to get it to work.
On a 148GTL about 50 parts to remove.

Crazy on not doing that.

Im looking for either the original channel selector.
or some other means to get something to work. Cheap money LOL

Or try 1 more time to fix the original which im sure i will be doing.

Again anyone out there have a parts radio?
Anyone have any suggestions for a replacement selector?

 

[Night Stalker10]

Well I just read up on the DDS encoder module for price and install, way to much in price and way to much to install.
Price around $125.00 and i install
About 5 PDFS to read up on install and how to get it to work.
On a 148GTL about 50 parts to remove.

Crazy on not doing that.

Im looking for either the original channel selector.
or some other means to get something to work. Cheap money LOL

Or try 1 more time to fix the original which im sure i will be doing.

Again anyone out there have a parts radio?
Anyone have any suggestions for a replacement selector?

I agree with you on the price. I've looked into those DDS encoders, and they cost more than what my radios are worth. I think they are the coolest mod you could do to an old radio today. Of course part of that price is the extra channels feature the module provides. I wish someone would offer the same module with just the normal 40 channels for about half the price. That would make it more tempting for me to spend the money on one.

 

[brandon7861]

I wasn't talking about DDS (direct digital synthesis), I was talking about a different device that only talked to the existing PLL using the ribbon coming off the old channel dial. Something that rolled through 40 channels on the LEDs but could have the 8 or 9 bits of binary for those 40 channels custom set to accommodate any radio.

It would be strictly a channel encoder replacement. No need to yank working xtals.

 

[Techno1]

I wasn't talking about DDS (direct digital synthesis), I was talking about a different device that only talked to the existing PLL using the ribbon coming off the old channel dial. Something that rolled through 40 channels on the LEDs but could have the 8 or 9 bits of binary for those 40 channels custom set to accommodate any radio.

It would be strictly a channel encoder replacement. No need to yank working xtals.

Thanks Brandon yes I know I brought up the DDS modules.
This selector has no ribbon cable just 7 wires from the bottom pc board and run over to the chassis where there are 7 post the the nine wires are wire wrapped to.

This is one of the few radios where they used a wire wrap gun to make connections to post on the main pc board no ribbon cables. that is then connected to the pll02A to change channels.
look over to the right side and you can see the post

So 1 middle wafer to change channels and the 2 outer ones for the 2 digit LeD display

 

[Techno1]

I agree with you on the price. I've looked into those DDS encoders, and they cost more than what my radios are worth. I think they are the coolest mod you could do to an old radio today. Of course part of that price is the extra channels feature the module provides. I wish someone would offer the same module with just the normal 40 channels for about half the price. That would make it more tempting for me to spend the money on one.

Hi Night Stalker10

Yes the DDS are way over priced and if you want installed its another $150.00.
Look a 40up and 40down kit is all you need for extra channels after that no one is on those channels.
So now I have a good working ssb base but the channels display need replaced.
I hope someone pops up with a parts radio and a good channel selector.