#80 Realistic HTX-100 diagnostic and repair

[Radio Tech]

#80 Realistic HTX-100 diagnostic and repair

In this video we take a donor radio and do a little troubleshooting to see just how bad a shape it is in. Since I already have one of these I will probably give this radio away to someone in need.

[The_Penguin]

I love a good repair video, even more so when it's a solid state ham rig.
Thanks for sharing!

[Radio Tech]

Thanks for watching. Not a lot here do so. All depending on what one likes 

[CJay]

Thanks for watching. Not a lot here do so. All depending on what one likes 

Well you can count me as a viewer too, I like a good repair video, in fact I've just repaired a Uniden 2830/President Lincoln and will be checking the alignment one evening this week.

[Radio Tech]

Thanks for watching. Not a lot here do so. All depending on what one likes 

Well you can count me as a viewer too, I like a good repair video, in fact I've just repaired a Uniden 2830/President Lincoln and will be checking the alignment one evening this week.

Great, Would be interested to know what you found wrong on the Uniden. Thanks

[CJay]

Thanks for watching. Not a lot here do so. All depending on what one likes 

Well you can count me as a viewer too, I like a good repair video, in fact I've just repaired a Uniden 2830/President Lincoln and will be checking the alignment one evening this week.

Great, Would be interested to know what you found wrong on the Uniden. Thanks

Common fault on Unidens in general but on the FM board there are a pair of caps wired back to back to make a bipolar/non polarised capacitor, they go short and cause extremely poor or no FM/AM receive, replaced with a proper non polarised part.

Trying to get approval to re-cap the whole radio, owner won't get a guarantee unless they agree.

It also had a faulty CPU which wasn't responding to two or three buttons, replacing it fixed that.

[The_Penguin]

Speaking of Uniden, I'm working on a BCD-996xt scanner that got fried probably by overvoltage.
Would kill for a schematic, but my searches of all the dark seedy corners of the internet have failed

[voltz]

Count me in too. I always watch your videos but dont always comment because you're doing a great job anyway!

[Radio Tech]

Common fault on Unidens in general but on the FM board there are a pair of caps wired back to back to make a bipolar/non polarised capacitor, they go short and cause extremely poor or no FM/AM receive, replaced with a proper non polarised part.

Trying to get approval to re-cap the whole radio, owner won't get a guarantee unless they agree.

It also had a faulty CPU which wasn't responding to two or three buttons, replacing it fixed that.

I always feel like recap solves a lot of problems. Make troubleshooting much easier in the long run. I know what you mean about back to back capacitors. Seen this in quite a few circuits and can be a trap for young players.

Speaking of Uniden, I'm working on a BCD-996xt scanner that got fried probably by overvoltage.
Would kill for a schematic, but my searches of all the dark seedy corners of the internet have failed

Always hard to find schematics for those. Not even sure if they ever released one. If I run across one will let you know.

Count me in too. I always watch your videos but dont always comment because you're doing a great job anyway!

Thanks brother. I get quite a bit of views now. I do not post as many videos on websites anymore. Seems it makes no difference if I do or not.  Biggest thing at the moment is keeping up with all the replies from folks. I am getting well over 100 emails a day.

[CJay]

Common fault on Unidens in general but on the FM board there are a pair of caps wired back to back to make a bipolar/non polarised capacitor, they go short and cause extremely poor or no FM/AM receive, replaced with a proper non polarised part.

Trying to get approval to re-cap the whole radio, owner won't get a guarantee unless they agree.

It also had a faulty CPU which wasn't responding to two or three buttons, replacing it fixed that.

I always feel like recap solves a lot of problems. Make troubleshooting much easier in the long run. I know what you mean about back to back capacitors. Seen this in quite a few circuits and can be a trap for young players.

I only repair radios for my own amusement or very good friends these days, I like the ones other techs have given up on so I have a habit of buying myself 'scrap' radios like your donor HTX100 to fix up and move on, I'm not that interested in using them once I've repaired them.

Three out of the four Uniden boarded radios I've had in 2016 had shorted caps so a recap would seem to be a sensible thing to do, maybe not as a first course of action unless I can attribute a fault to it but for reliability as much as anything else.

Had the discussion on other forums where recapping is seen as a waste of time by the screwdriver experts but my experience and test gear tells me it's often worth it.

[Radio Tech]

Common fault on Unidens in general but on the FM board there are a pair of caps wired back to back to make a bipolar/non polarised capacitor, they go short and cause extremely poor or no FM/AM receive, replaced with a proper non polarised part.

Trying to get approval to re-cap the whole radio, owner won't get a guarantee unless they agree.

It also had a faulty CPU which wasn't responding to two or three buttons, replacing it fixed that.

I always feel like recap solves a lot of problems. Make troubleshooting much easier in the long run. I know what you mean about back to back capacitors. Seen this in quite a few circuits and can be a trap for young players.

I only repair radios for my own amusement or very good friends these days, I like the ones other techs have given up on so I have a habit of buying myself 'scrap' radios like your donor HTX100 to fix up and move on, I'm not that interested in using them once I've repaired them.

Three out of the four Uniden boarded radios I've had in 2016 had shorted caps so a recap would seem to be a sensible thing to do, maybe not as a first course of action unless I can attribute a fault to it but for reliability as much as anything else.

Had the discussion on other forums where recapping is seen as a waste of time by the screwdriver experts but my experience and test gear tells me it's often worth it.

That is where they don't understand. A lot of these screwdriver experts don't realize the stuff they are working on was built cheap down to a price. And being built cheap means they used cheap capacitors.  Like the HTX-100 I worked on had a bad YEC branded cap. Rest are Rubycon. CB radios use what ever they could get cheap. Cheap don't last long. I like Mike at Mikes Radio Repair, he changes all the caps in every radio that comes in.

[The_Penguin]

That is where they don't understand. A lot of these screwdriver experts don't realize the stuff they are working on was built cheap down to a price. And being built cheap means they used cheap capacitors. 

One day I'll post a photo of the bag 'o caps I've replaced over the last 6 years. I mainly repair LCD monitors, TVs, and assorted other devices with SMPS (printers, IP phones) as a hobby, and the amount of bad caps is staggering. My spreadsheet says I've use 283, but I suspect it's more than that in the bad bag.

[CJay]

That is where they don't understand. A lot of these screwdriver experts don't realize the stuff they are working on was built cheap down to a price. And being built cheap means they used cheap capacitors.  Like the HTX-100 I worked on had a bad YEC branded cap. Rest are Rubycon. CB radios use what ever they could get cheap. Cheap don't last long. I like Mike at Mikes Radio Repair, he changes all the caps in every radio that comes in.

Absolutely, the Cybernet chassis' seem to use decent quality all through but after 25-35 years, they'd benefit too.

Hate the mythology that those screwdriver experts help create.

A random sampling of the caps in the radio on the bench right now (picture) hasn't found any out of spec but as it's my radio I might just do it anyway

[Radio Tech]

One day I'll post a photo of the bag 'o caps I've replaced over the last 6 years. I mainly repair LCD monitors, TVs, and assorted other devices with SMPS (printers, IP phones) as a hobby, and the amount of bad caps is staggering. My spreadsheet says I've use 283, but I suspect it's more than that in the bad bag.

It is amazing how these things pile up. Mike over at mikesradiorepair on YouTube (one of the best honest cb radio techs I have ever seen.) He will not work on a older unit unless he can recap the thing.  He saves all the caps and recycles them. Several 5 gallon buckets at a time.

That is where they don't understand. A lot of these screwdriver experts don't realize the stuff they are working on was built cheap down to a price. And being built cheap means they used cheap capacitors.  Like the HTX-100 I worked on had a bad YEC branded cap. Rest are Rubycon. CB radios use what ever they could get cheap. Cheap don't last long. I like Mike at Mikes Radio Repair, he changes all the caps in every radio that comes in.

Absolutely, the Cybernet chassis' seem to use decent quality all through but after 25-35 years, they'd benefit too.

Hate the mythology that those screwdriver experts help create.

A random sampling of the caps in the radio on the bench right now (picture) hasn't found any out of spec but as it's my radio I might just do it anyway

Yep, replace them and get many years of service. Is that a Jumbo?

[CJay]

It is, Mk1 PTBM059 and it'd never seen a soldering iron before I opened it.

The only fault with it was a failed trimmer capacitor on the 10.695 carrier crystal, it was approximately 4KHz off and would only trim a  few Hz, replaced that and it's working fine now it's all aligned properly.

A few white LEDs for the signal meters and it'll be up for sale soon.

The Mk2 PTBM121 I own has been hacked about quite a lot unfortunately.

[The_Penguin]

It is amazing how these things pile up. Mike over at mikesradiorepair on YouTube (one of the best honest cb radio techs I have ever seen.) He will not work on a older unit unless he can recap the thing.  He saves all the caps and recycles them. Several 5 gallon buckets at a time.

Great, I just watched a bunch of Mike, Buddy and Peter's repair videos. In addition to test-equipment envy, I now have the urge to restore my old Yaesu 757 GX.
It needs a Metric shipload of diodes,  a battery, and I may as well re-cap it while I have the RF board out to do the diodes.

[twistedxknights]

thanks for the Video , I have a htx-100 at the moment that seems to be working fine just has lower then advertised output ( approx around 15 watts on ssb) so for the moment I live with it though it seems like the 10m band is dead in my area so I have it up for sale/trade on QRZ.

I do have 2 other ham radios that are in need of repair one is a yeasu ft-4700h and the other is an ICOM IC-232.