GE Superbase info needed

[Deleted]

I have aquired a GE Superbase for exchange of services. My friend gave this to me and is supposed to be stock and fully working. Looks fantastic. However, he said the deadkey was turned up to 6 watts AM, 24 watts SSB. OUCH!

I am going to turn this back. Could he have damaged it running this high? What are the AM and SSB power adjustments?

[Sandbagger]

Aug 8, 2009 20:02:30 GMT -5 @vinnies said:

I have aquired a GE Superbase for exchange of services. My friend gave this to me and is supposed to be stock and fully working. Looks fantastic. However, he said the deadkey was turned up to 6 watts AM, 24 watts SSB. OUCH!

I am going to turn this back. Could he have damaged it running this high? What are the AM and SSB power adjustments?

The GE Superbase is Cybernet chassis radio similar to that Colt Black Shadow you worked on a while back. The AM power is controlled by the wire-wound rheostat (marked VR1 on the schematic). I've never worked on a Cybernet radio that would exceed 15 or 16 watts PEP, so I tend to think that 24 watt figure is a little "optimistic". I wouldn't sweat it too much if the ALC for SSB is cranked wide open.

The Schematic is on CB tricks, but it's a little tough to follow. Like other Cybernet factory schematics it's laid out somewhat cluttered.

[Deleted]

Thanks. I might have to get it printed at Staples. Do you have the unlocked clarifier mod for this radio?

[Sandbagger]

Aug 9, 2009 7:55:53 GMT -5 @vinnies said:

Thanks. I might have to get it printed at Staples. Do you have the unlocked clarifier mod for this radio?

I don't have a step-step mod, but if you look at the circuit, it should be similar to what you would do to a Telsat SSB-140 or the Colt Black Shadow.

[Deleted]

Dave,

I want to use a dynamic mic, maybe one of those studio Radio Shack or a Heil Handi Mic. The Radio Shack impedance is not listed. The Heils Handi Mic is about 600 ohms. Can I get this to work with the Superbase? I do not want to use a power mic with this rig.

[Sandbagger]

Aug 9, 2009 22:21:49 GMT -5 @vinnies said:

Dave,

I want to use a dynamic mic, maybe one of those studio Radio Shack or a Heil Handi Mic. The Radio Shack impedance is not listed. The Heils Handi Mic is about 600 ohms. Can I get this to work with the Superbase? I do not want to use a power mic with this rig.

You should be able to get it to work, as long as the mic is not a balanced load (3 wire, usually XLR plug). In that case you'd need an audio BALUN transformer to properly match the impedence to the radio. If the mic has only 2 wires (one being a shield), you should be ok. Most solid state radios are designed to use a 500-1000 ohm low impedence microphone.

I'm not sure if the mic will have enough output level to drive the radio adequately. You may have to eat it to make 100% modulation, and I'm never a fan of that. The Superbase has a speech compression circuit in it which may boost your input level enough. But it never hurts to experiment. That's half the fun......

[Deleted]

I need a power cord for this. The guy has one and cannot find it. I do not want to hack the back panel to out in an updated power cord.

[mark4]

I have owned 2 of them. And they were both problematic.
Both had open circuit traces in the same place.
Fixed them and put them up for sale.
I have talked to more than one tech about this radio.
That has far more experience with them than I have. They said stay away from them. Just a thought.

[jacobs132]

i have heard the same thing about them being problematic, i guess thats why you see them on ebay, sure is a nice looking radio though, i have been temted a few times to purchase one

[Deleted]

I heard that here, too. But they sure are pretty and it was free. Did the traces open up or lift and break?

[2600]

Cybernet used double-sided pc boards to build this radio.

The most-common problems are with the top-side foil traces.

The holes that have a foil trace on both top and bottom will use a tiny copper pin called a "griplet" to connect the top-side foil to the bottom side. The temperature coefficient of expansion for these pins does not match the solder's temperature coefficient. Once enough heat/cool cycles happen, fatigue cracks develop around the griplet pins.

Most aggravating problem I had with these was the final's tendency to oscillate on SSB transmit. Adding some ferrite beads to the "bias test" jumpers helped most of the time.

I tell anyone who wants to use one of these to set aside a budget for regular repair expenses.

When they work they're okay. The trouble is with how often they break down.

73

[Deleted]

Nomad,

Should I replace the griplet pins with like bare copper wire and resolder? How many are there?

[Deleted]

Question. This is a Cybernet chassis. The underside of the PCB has a VCO block with a slug in it. The slug is chipped, and it was epoxied! I mean the 2 part epoxy! I hope it don't need alignment.

Anyway, what are other similar chassis that would have that VCO block? If it needs replacement, I would have to get a scrap unit. Thanks.

[Sandbagger]

Aug 23, 2009 8:56:38 GMT -5 @vinnies said:

Question. This is a Cybernet chassis. The underside of the PCB has a VCO block with a slug in it. The slig is chipped, and it was epoxied! I mean the 2 part epoxy! I hope it don't need alignment.

Anyway, what are other similar chassis that would have that VCO block? If it needs replacement, I would have to geta scrap unit. Thanks.

That's the VCO block and any of the Cybernet SSB chassis radios will have it.. Look at the Lafayette Telsat SSB 80, 120, 140. Any Hy-Gain, G.E., RCA, J.C Penney, Colt, and some Midland SSB radios.

[Deleted]

Super job, Dave! (No pun intended on Superbase)

Do they have to be specifically SSB radios or 40 channel? I have a scrap Gemtronix GTX-77 (23 channel). Is that a compatible?

[Sandbagger]

Aug 23, 2009 10:38:31 GMT -5 @vinnies said:

Super job, Dave! (No pun intended on Superbase)

Do they have to be specifically SSB radios or 40 channel? I have a scrap Gemtronix GTX-77 (23 channel). Is that a compatible?

As far as I know, only the 40 channel SSB chassis radios have the VCO block. The AM rigs use an "open" VCO circuit. If you really wanted to (and you were up for a real challenge), you could build the circuit in the VCO block. It's only a varactor diode, a coil, 6 caps and 2 resistors.

[Deleted]

I didn't want to build one. Were all these the same? It appears the Gemtronix is a metal case.

If it is not the same, no biggie. My radio club is having a hamfest on Sept 20.

[Sandbagger]

Aug 23, 2009 22:32:07 GMT -5 @vinnies said:

I didn't want to build one. Were all these the same? It appears the Gemtronix is a metal case.

If it is not the same, no biggie. My radio club is having a hamfest on Sept 20.

All the VCO blocks I've seen are covered by a metal case and, with the exception of the DAK MK10, the circuit inside is encased in epoxy. There should be 5 pins, 3 on one end and 2 on the other end.

[Deleted]

Here is an update. I was replacing the meter lights with LEDs, when one of th solder tabs on the meter broke off. I ended up removing the meter, ripping it apart, and soldering a 3 inch jumper to the broken tab. I then has to drill out the plastic casing to allow the wire to fit thru the back. There it was, meter coil, etc, all in pieces. I was ever so careful. Put it back together with scotch tape. And guess what, it works!

BTW, this is one of those classis mis-rated radios. This radio was given to me for services to be performed. I was told this was mint and you can eat off of it. Neither is true. This radio is used, but I would rate it a very good. I rate radios based on mint, near mint, very good, good, fair, poor. This is nowhere near mint or near mint. But it is better than good. It amazing how different people regard mint or near mint. People simply don't realize that mint is basically out of the box new, or stored and never used. Also, it needed a disassembly and wash in Krud Kutter took it from good to very good.

[Deleted]

Receive is a little weak on this radio. It cannot touch my TRC-455 on receive. I need to align the receive, but the Sams CB-234 is a bit hard to find.

[zman]

All the GE superbases ive seen were pretty well hacked up.

[radionut57]

I realize this is a old thread, I picked one up yesterday, beautiful condition, everything seems to work fine, the issue I'm having is it didn't come with the mic, I found a old kraco hand mic, that works only on AM, it'll occasionally move the needle on SSB as soon as you unkey mic and try to key up again there's no movement, like I mentioned it works fine on AM , perhaps the mic is the issue, its a oldie.. any feedback would be welcome 73 Rick

[Sandbagger]

Apr 1, 2023 15:25:40 GMT -5 radionut57 said:

I realize this is a old thread, I picked one up yesterday, beautiful condition, everything seems to work fine, the issue I'm having is it didn't come with the mic, I found a old kraco hand mic, that works only on AM, it'll occasionally move the needle on SSB as soon as you unkey mic and try to key up again there's no movement, like I mentioned it works fine on AM , perhaps the mic is the issue, its a oldie.. any feedback would be welcome 73 Rick

I assume you are talking into the mic when you transmit on SSB? There isn't a carrier on SSB so there won't be any power out until you talk. Are you sure there is modulation on AM?

[bountyhunter]

Thanks 2600. I had forgotten the double sided circuit bds from the 80's. Not a good time to be working in a TV shop. Repeated call backs, ANGRY, RUDE customers missing their TV time. I came up with a fix for those nasty little bubbling eyelets. Heat the eyelet until it starts bubbling and stick a small copper wire thru it until it comes out the other side. Add a little flux and it actually shines, no more bubbles. Never had another call back, for that problem.

[Sandbagger]

Mar 26, 2024 0:37:02 GMT -5 bountyhunter said:

Thanks 2600. I had forgotten the double sided circuit bds from the 80's. Not a good time to be working in a TV shop. Repeated call backs, ANGRY, RUDE customers missing their TV time. I came up with a fix for those nasty little bubbling eyelets. Heat the eyelet until it starts bubbling and stick a small copper wire thru it until it comes out the other side. Add a little flux and it actually shines, no more bubbles. Never had another call back, for that problem.

That's how I dealt with plated through holes as well.It seemed to work well.