Jump to content
IGNORED

Any reason to keep the modulator in a 600XL?


bfollowell

Recommended Posts

I'm pretty sure the answer is a resounding no, but I thought I'd ask anyway.

 

I have a filthy, non-working 600XL that I bought as a winter project. I'm going to clean and restore it and, hopefully, get it running again. Assuming I do, I plan to upgrade it to 64K and install a UAV and a monitor port. I'll probably re-home it after that. My question concerns the RF modulator. Is there any reason at all to keep it? I mean, I figure almost no one in their right mind would want to use RF if there were any other options at all. I'll be removing the channel select switch to install the monitor port, so I figure RF wouldn't work anyway. That being said, is there any reason at all to leave the modulator in place? My reasoning is that, it takes up a fair amount of real estate on an already small motherboard. I figured it would make more sense to remove it altogether so that any future owner could maybe use that space for some other upgrade.

 

Opinions?

 

Link to comment
Share on other sites

No good reason to keep it really*, but they are a pain to remove and the only reason is to make room for something else (VERY understandable when it comes to the 600XL and it's lack of space inside) or to get rid of interference from it through video output. I don't think that is a factor at all though with UAV's and similar video board upgrades that use their own isolated video paths.. I've removed RF's from 3 1200XL's and an 800XL, though I didn't remove the one in my 800, but I did disconnect it, but I did this to them all because I still use the original (DIY fixed and/or upgraded) video circuits for output. At least until my Sophia 2 for my 800 arrives, and I get around to buying a VBXE for my main 1200XL.

 

*The only reason to have RF's any more is for those who want to keep everything stock and original for collector's purposes mostly.

Edited by Gunstar
Link to comment
Share on other sites

Almost none. But a very experienced user once told me that rarely he would come across a 600XL that has really nice RF.  The odds are against it (from my own experience), but you might check before deciding to rip it out. 

 

It always amazed me how poor the RF in the Atari is as compared to other devices such as Super Nintendo, etc.  I did use the RF originally with my 800, but immediately longed for something better.  I finally got a monitor with S-video in the mid-80's and was just astounded how much better the display quality was. When upgraded, the 600XL is really cool!

 

How about posting a couple of "before" pictures? 

 

 

Link to comment
Share on other sites

19 minutes ago, Larry said:

Almost none. But a very experienced user once told me that rarely he would come across a 600XL that has really nice RF.  The odds are against it (from my own experience), but you might check before deciding to rip it out. 

 

It always amazed me how poor the RF in the Atari is as compared to other devices such as Super Nintendo, etc.  I did use the RF originally with my 800, but immediately longed for something better.  I finally got a monitor with S-video in the mid-80's and was just astounded how much better the display quality was. When upgraded, the 600XL is really cool!

 

How about posting a couple of "before" pictures? 

 

 

Oh, I plan to. It was listed as "for parts". I know for certain that it won't work when I try to power it up because, at the very least, it's missing the Antic chip. I'm hopeful, but not very, that maybe that will be all that's wrong with it. I don't want to spend any more on it until I know I can get it running, so I'll be using the RF myself, at least until I see proof of life. After that, I'll probably look into the UAV and monitor port.

 

Oh, and it was missing its case screws too, so I'll need to see if I can find a decent replacement screw.

 

Here's the auction photos of it in its current condition.

 

 

s-l500.jpg

s-l1600.jpg

s-l1600 (1).jpg

Edited by bfollowell
  • Like 1
Link to comment
Share on other sites

9 hours ago, Gunstar said:

but they are a pain to remove

I don’t think they are, really. I use @flashjazzcat’s method, as demonstrated on a couple videos: clear the row of vias for the connecting signals; then heat up the soldered tab closes to the back edge of the board using the largest tip you have on your iron to help deal with the large thermal mass of the modulator can. As that back-most soldered tab heats up, slide a thin jeweler’s screwdriver between the PCB and the can and slowly lever the can off the board. Repeat the same basic procedure for each solder tab on the modulator can until it’s free. It only take a few minutes if you’re patient and methodical. 

  • Like 2
Link to comment
Share on other sites

10 minutes ago, DrVenkman said:

I don’t think they are, really. I use @flashjazzcat’s method, as demonstrated on a couple videos: clear the row of vias for the connecting signals; then heat up the soldered tab closes to the back edge of the board using the largest tip you have on your iron to help deal with the large thermal mass of the modulator can. As that back-most soldered tab heats up, slide a thin jeweler’s screwdriver between the PCB and the can and slowly lever the can off the board. Repeat the same basic procedure for each solder tab on the modulator can until it’s free. It only take a few minutes if you’re patient and methodical. 

I wonder if this is a job that would work better, or worse, using a hot air rework station?

 

If worse, I may need to pickup a couple of larger chisel tips for my Weller.

 

Link to comment
Share on other sites

4 minutes ago, bfollowell said:

I wonder if this is a job that would work better, or worse, using a hot air rework station?

 

If worse, I may need to pickup a couple of larger chisel tips for my Weller.

 

I doubt it - using an iron will let you keep the heat concentrated on just the solder points. Seriously, it’s not hard at all to get these off. Just use the widest tip you have and maybe turn up the heat by 25 degrees or so if necessary. It’s actually much harder to describe the technique than it is to actually do it. 

  • Like 2
Link to comment
Share on other sites

37 minutes ago, DrVenkman said:

I don’t think they are, really. I use @flashjazzcat’s method, as demonstrated on a couple videos: clear the row of vias for the connecting signals; then heat up the soldered tab closes to the back edge of the board using the largest tip you have on your iron to help deal with the large thermal mass of the modulator can. As that back-most soldered tab heats up, slide a thin jeweler’s screwdriver between the PCB and the can and slowly lever the can off the board. Repeat the same basic procedure for each solder tab on the modulator can until it’s free. It only take a few minutes if you’re patient and methodical. 

I suppose I didn't take into account that I don't have any large/wide tips for my solder iron, only the normal DIP size tips and fine for surface mount.

Link to comment
Share on other sites

1 minute ago, Gunstar said:

I suppose I didn't take into account that I don't have any large/wide tips for my solder iron, only the normal DIP size tips and fine for surface mount.

It may depend on your Iron, I use the same tip on mine for all jobs, but I have a temperature control that

I can set to increase the heat for larger jobs, does yours allow temp adjustment ?

Link to comment
Share on other sites

Just now, TGB1718 said:

It may depend on your Iron, I use the same tip on mine for all jobs, but I have a temperature control that

I can set to increase the heat for larger jobs, does yours allow temp adjustment ?

Yes, I have a nice iron with temperature control, but it's been over a decade since I removed any modulators and back then I had a cheap Radioshack iron too.

Link to comment
Share on other sites

4 minutes ago, tjlazer said:

I still use my 64k 600XL with RF on an old CRT TV and after I removed the blurring cap, the video is pretty good.  I decided to leave it as is for now.

 

Not bad for RF, but definititely not up to UAV/composite quality. If I can get this one running, I definitely plan to install a UAV and a monitor port, as well a remove the modulator.

 

Link to comment
Share on other sites

2 hours ago, bfollowell said:

I wonder if this is a job that would work better, or worse, using a hot air rework station?

No, no... no, no, and no. :) You risk cooking and blistering the PCB.

 

Iron with good heat delivery, chisel tip. You want something which will melt all the solder around those metal lugs as fast as possible. See the YouTube video I'll be uploading in a few hours.

53 minutes ago, bfollowell said:

Not bad for RF, but definititely not up to UAV/composite quality.

The 600XL featured in the aforementioned video (available this evening) has stunning Y/C video which would arguably make UAV redundant. RF modulator and C109 removed, and I was pretty shocked by how good it looks on an LCD.

  • Like 3
Link to comment
Share on other sites

40 minutes ago, flashjazzcat said:

No, no... no, no, and no. :) You risk cooking and blistering the PCB.

 

Iron with good heat delivery, chisel tip. You want something which will melt all the solder around those metal lugs as fast as possible. See the YouTube video I'll be uploading in a few hours.

The 600XL featured in the aforementioned video (available this evening) has stunning Y/C video which would arguably make UAV redundant. RF modulator and C109 removed, and I was pretty shocked by how good it looks on an LCD.

Well, like I said, assuming I can get this one running, I'll be using RF initially anyway, so I'll definitely check it out.

 

51 minutes ago, manterola said:

After you remove the channel switch, you can still use RF.  So why not to keep it? 

If I remove the channel switch, how would I be able to still use RF? How would I go about selecting which channel to output the video to?

 

Link to comment
Share on other sites

1 hour ago, flashjazzcat said:

The 600XL featured in the aforementioned video (available this evening) has stunning Y/C video

NTSC or PAL? I don't think my NTSC 600XL's have fully-populated video circuits for use with a DIN jack. So the easiest install for North American folks is something like a UAV and then wire the outputs directly to the DIN. Otherwise we have to find/figure out the expected values for the missing discrete components.

Link to comment
Share on other sites

17 minutes ago, DrVenkman said:

NTSC or PAL? I don't think my NTSC 600XL's have fully-populated video circuits for use with a DIN jack. So the easiest install for North American folks is something like a UAV and then wire the outputs directly to the DIN. Otherwise we have to find/figure out the expected values for the missing discrete components.

I should’ve mentioned. It’s an NTSC model.

 

I see what @manterola means though. On the schematic it looks like the channel selector switch just shorts a pin on the modulator to ground for one channel and I guess it stays high for the other one. So I guess the modulator signal would still be there for one channel or the other, even after I remove the channel select switch to install the monitor port. If that’s the case, I guess I’ll wind up leaving it in there after all.

 

 

Link to comment
Share on other sites

6 hours ago, Larry said:

It always amazed me how poor the RF in the Atari is as compared to other devices such as Super Nintendo, etc.  I did use the RF originally with my 800, but immediately longed for something better.

 

To be fair, you're comparing 1979-era hardware with a console that launched in 1990.  It's not surprising that the SNES does (subjectively) better given that RF output improved a lot over the course of the 1980s.

 

Having said that, I don't disagree with you re: Atari's RF output quality.  My STs were light-years better than any of my A8s ever were in that regard.  Hell, my even 7800 looks amazing by comparison.  However, my recollection of how my PAL A8s looked on a native PAL CRT seems to indicate that they were sharper than their NTSC counterparts by quite a wide margin.  Of course, that could also be 35-plus-year-old memories being particularly rose-tinted.

Edited by x=usr(1536)
  • Like 1
Link to comment
Share on other sites

35 minutes ago, bfollowell said:

Well, like I said, assuming I can get this one running, I'll be using RF initially anyway, so I'll definitely check it out.

 

If I remove the channel switch, how would I be able to still use RF? How would I go about selecting which channel to output the video to?

 

Jumper the vias.  Yes, you'll effectively be hard-wiring the channel selection, but short of a switch on a ribbon cable or cutting another hole in the 600's case to mount one in, I don't see a good way to make it happen.

 

Funnily enough, I'm actually running up against the same consideration with my 5200, but I'll cross that bridge once the power issues have been sorted out (and the modulator reinstalled).

Edited by x=usr(1536)
Link to comment
Share on other sites

43 minutes ago, DrVenkman said:

NTSC or PAL? I don't think my NTSC 600XL's have fully-populated video circuits for use with a DIN jack. So the easiest install for North American folks is something like a UAV and then wire the outputs directly to the DIN. Otherwise we have to find/figure out the expected values for the missing discrete components.

PAL. I get what you mean about the NTSC machines being a headache to populate. I suggested it to a 600XL owner on Facebook, though, as an interesting challenge nevertheless (for those that way inclined).

  • Like 1
Link to comment
Share on other sites

I agree: the quality of PAL svideo is good. I did not install UAV in that, just some mods are needed to have both chroma and lumma. 

The NTSC instead does not have a bunch of components to complete the monitor output circuit. So it is super easy option to add an UAV. 

Now regarding the modulator, I remember someone in the forum remove it to add an internal sio2midi board. That looked cool.

Edit: yep, after removing the channel select swich, the modulator gets stuck in channel 2 if I remember correctly. 

Edited by manterola
Link to comment
Share on other sites

Unless you really need the space I'd say keep the RF modulator in, then you've got an additional option to hook it up to a TV.

 

Last year I bought a new TV, an LG OLED 55C8, and here in Europe (models seem to vary in different parts of the world) it doesn't have any analog composite/s-video/RGB inputs. But it still supports analog RF input, so that's the only possibility to hook up an Atari to that TV without needing any additional devices/converters/...

 

RF video quality surely isn't too great but at least it's a possibility to get a picture without investing $$$ into some analog to HDMI converter.

 

Not sure how long old, analog RF will be supported by TVs (analog terrestrial was killed here long ago and most cable providers transitioned to DVB-C too, so probably will stop analog sooner or later), but that option might buy you a bit of time until analog stuff is finally phased out completely.

 

so long,

 

Hias

Link to comment
Share on other sites

7 hours ago, manterola said:

Edit: yep, after removing the channel select swich, the modulator gets stuck in channel 2 if I remember correctly. 

 

Assuming this is right (and Channel 2 isn't in use in your area), just run without the switch until you can find one.  If Channel 2 is in use, you can still try using it, but depending on broadcast signal strength expect varying degrees of interference with the 600XL's video output.

 

2 hours ago, HiassofT said:

Unless you really need the space I'd say keep the RF modulator in, then you've got an additional option to hook it up to a TV.

 

Agreed.  NTSC 600XLs don't have a native fallback option for video output like PAL models do, and since leaving it in won't affect video quality on the composite output, there isn't really much point in taking it out.

Link to comment
Share on other sites

In my area, and I assumed this was across the nation (US), but maybe not, on broadcast TV there is only ONE analog station left, all broadcast stations are now digital, and that one station that is analog is an unused (static) channel that is specifically there for old farts like us to hook up our old equipment to RF. That is channel 3. That, of course, is only when using modern TV's and letting it auto-program the channels. Of course if you have an old CRT that you can manually turn to what would be an empty analog station, then channel 2 would be there to use. Channel 2 is a digital broadcast in my area and cannot be used for analog RF in my area on modern TV's as far as I know. Admittedly, I don't know much about it all though; I just recently gave up cable/satellite TV and started using only broadcast TV. Since I now use streaming services for 90% of my viewing. 

Edited by Gunstar
  • Like 1
Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...