Palomar Skipper 300 - worth the effort?

[KF7VZZ]

I was gifted a Palomar Skipper 300 that had been sitting in a neighbor's garage for nearly ten years. Dust and Rust inside, but everything appears to be in place although it's missing knobs. With the description below, do you think it would be worth the "making it work" restoration? I'm not interested in CB, but an extra kick on 6m or 10m would be nice occasionally. There's a matching (in age) CB to go with it, but it doesn't power up due to a bad transformer.

I powered the Skipper up and saw two of the 6lf6's glow (driver and one final), but the fan didn't spin so I powered down. The fan is rusted in place! I swapped tube positions and all four glowed. It's been powered off since then. Yes, I unplugged it and kept the left hand in pocket while inside. Other than that everything is just dirty and Not Very Good Looking. (bakelite tie strips, not PCB)

I'm leery of just hooking it to the radio and doing the tune-up without first doing more, but where do I start? Or should I just bite the bullet and fire it up? If it works I'll probably try to find a 120VAC fan or see if a newer 12VDC will work in its place. I'm not capable of spending much, but I keep a fairly stocked junk^H^H^H^H parts-bin where the XYL doesn't mind too much. :rolleyes: No one around here has a tube tester, either.

Thanks for any comments! (good or bad)

linky: http://www.cbtricks.com/Amp/palomar/skipper_300/index.htm

[W4AFB]

Id trash that turd. Not worth investing money into. IMO

[KB4QAA]

I can't see putting money into a rusted old CB amp...

[WG7X]

Id trash that turd. Not worth investing money into. IMO

Amen!

It's nothing but a low priced piece of CB crap. The best thing to do with it involves a drop from a rooftop followed by application of a small sledge hammer and finishing up with a broom and dustpan.


73 Gary

[KE3WD]

These hams are giving you the straight dope, the four-one-one.

Unfortunately.

At least you didn't pay money for it.

Just please, don't put it on the ham bands. It likely makes all kinds of junk happen on 6 when you are on 10 (or 11).

Also, it was made to work with about 4 to 10 watts drive. Hit it with any more than that, like the standard ham 100 and if it doesn't make smoke city, it will REALLY throw some spurs before it croaks.

Put it on the shelf as a conversation piece or exhibit.

BTW, the Sweep Tubes in that thing now cost way too much money, IF you can find 'em.

73

[KF7VZZ]

I think the consensus is... pretend I'm 5 again and taking apart dad's alarm clock so he can't get up in the morning.

Thank you gentlemen, this forum yielded far more value than the amp is apparently worth!

73
Mike

[KD8NPB]

Loot the transformer, HV caps, and variable caps.

Sell the tubes.

Make a new, better amp.

[WB0LSR]

Predictably there is always responses that trash CB gear without a second thought, and truthfully most of it is a bit lousy in terms of quality, but there isn't a single piece of RF gear I've found (regardless of it's intended use) that isn't potentially a source of parts for my own projects. It seems that as the years pass, certain "boat anchor" era parts are becoming harder and harder to find.. I agree with the statements so far that suggest parting it out and keeping what you can for possible future building.

[KA5LQJ]

Well,

It would make a good "boat anchor" while drift fishing, LOL! All of those early
model CB amps were "Class C" modulation. In other words, they throw spikes
and distortion from HELL. You don't want a citation from the F.C.C.

If you want a "clean" amp, build it yourself and in a Class AB1 configuration,
You can expect no more than 40% efficiency, but you will have great audio.
I'd use the amp on 10 FM as AM and SSB do well with low power on 10.

Personally, the ONLY thing I'd keep would be the transformer. When 10 is
'open' you can work the world with .5 watts, CW. I know because last cycle,
I worked the World, 'mobile' with an HR-2510 (17 watts out) and a 3' center-load, "Trucker's Special", LOL! I'm looking =forward to Cycle 24. ;-)

Respectfully submitted,
73,

Don S./KA5LQJ
8Q3224 <==CB, 1961
KKR2747 <== CB 1965
KOR0528 <== CB 1972
KAMF7712 <== CB 1980
Area_5_Wx_Group
N.B.S.R.C. - Chapter 2
QCWA

[WA7KKP]

[QUOTE=KA5LQJ;2219399] edited

Well,

It would make a good "boat anchor" while drift fishing, LOL! All of those early
model CB amps were "Class C" modulation. In other words, they throw spikes
and distortion from HELL[COLOR=red][COLOR=black]. You don't want a citation from the F.C.C.
;-)

Respectfully submitted,
73,

Don S./KA5LQJ

What Don is saying is that some CB amps are biased to Class C operation, which is NOT LINEAR. Any amplitude modulated signals (AM or SSB) are distorted beyond recognition. FM and CW signals are okay though.

ISTR that some amps do have a bias circuit -- you can check if there is by metering the plate current without drive, and the amplifier keyed up, which should be in the neighborhood of 50-60 ma. There's usually a pot and circuitry for setting that; if not, just add one.

CB amps as built aren't very good -- 99.99% use sweep tubes, and have been used as an AM linear, so the condition of the finals are usually questionable. Replacement tubes are expensive -- CBers tend to suck them (no pun intended here) down to nothing, replacing them with NOS tubes and driving up the prices. At least the box is okay; just be prepared to install a low pass filter on the output, and checking the bias circuitry for class AB linear operation. Just watch the drive -- most amps only tolerate 4 watts or so input. Overdriving them will cause all sorts of QRM over the spectrum, and that kills tubes PDQ.

Gary WA7KKP

[W8ZNX]

Predictably there is always responses that trash CB gear without a second thought, and truthfully most of it is a bit lousy in terms of quality, but there isn't a single piece of RF gear I've found (regardless of it's intended use) that isn't potentially a source of parts for my own projects. It seems that as the years pass, certain "boat anchor" era parts are becoming harder and harder to find.. I agree with the statements so far that suggest parting it out and keeping what you can for possible future building.

as it sits
it is junk

but as parts
it's a good find

you could make
FB little glow bug cw transmitter
out of the parts

yours truly
mac

[KC7QNM]

Give the amplifer a workout. Hook it up to a load and tune it up,use no more than ten watts to excite the amp...Palomar amps work pretty well when a tuner is in line as it reduces the possibilty of undesired signal..and a low pass filter also can help in keeping a clean signal if sympton's are present in output. Polomar amps like the one you have were often designed with sweep tube's and many operators built thier own amps...or purchased a sweep tube transciver...example's are SWAN gear,Heath gear, and every ARRL Handbook for 40years included sweep tube amplifer's up to 500 watts or the 200 watt level, some very the tubes used even more common older yeasu gear used sweep tubes in the finals. It requires a respect for sweep tubes ...it has added to the ham radio art's, that sweep tubes provided a once popular place in an operators shack.

[KF7VZZ]

Give the amplifer a workout. Hook it up to a load and tune it up,use no more than ten watts to excite the amp...

Since my last post, I did try just that. Turns out more than dust got into it over its time in storage, and I got a jolt as I powered it up. It's all parts now, the fuse block and other plastics disintegrated by time and weather.

So, I'm closing this thread as far as attempting to resurrect the Skipper. But now there's parts to be had, you might see a few on the sale thread later. I'm testing parts before I actually try to use them, still looking for a local tube tester...!

Thanks for all the varying advice! You never know what you're gonna get.

73
Mike

[W8JI]

Give the amplifer a workout. Hook it up to a load and tune it up,use no more than ten watts to excite the amp...Palomar amps work pretty well when a tuner is in line as it reduces the possibilty of undesired signal..and a low pass filter also can help in keeping a clean signal if sympton's are present in output. Polomar amps like the one you have were often designed with sweep tube's and many operators built thier own amps...or purchased a sweep tube transciver...example's are SWAN gear,Heath gear, and every ARRL Handbook for 40years included sweep tube amplifer's up to 500 watts or the 200 watt level, some very the tubes used even more common older yeasu gear used sweep tubes in the finals. It requires a respect for sweep tubes ...it has added to the ham radio art's, that sweep tubes provided a once popular place in an operators shack.

There are a lot of misconceptions in the post above.

First, a low pass does not clean up distortion or splatter problems. A low pass only cleans up harmonics that are far above the operating band.

Second, it is not safe to just plug in old unsafely built CB gear and see if it runs. The stuff often wasn't even close to safe when new, so be careful.

Third, most CB amps are built to intentionally distort the signal through self-biasing. This is to make meters swing and audio sound processed. None of this type of stuff really belongs on Ham bands, unless it has been verified to not have splatter and trash. Again external filters will NOT clean up or affect splatter or trash.

Ten meters is going to become a real mess from all the CB junk that is floating around. It isn't the fact it is a sweep tube that matters. It is the fact CB amps traditionally used self-bias to allow a variety of drive powers to be used, and to give the amps "audio" and "swing". They fit better on the CB band, not on ham bands.

73 Tom