what amp is this

[skybolt58]

I was told this was the skipper 300, but it is not! the skipper has 3 relays and this one has 2. and this one has the 6LX6 tubes in it. It says SCP and I cant find any info .. it has stopped keying up and I feel it is to do with the 2 relays on that small board.

here are what pics I have

 

[Quiksilver]

Here's some old info from eham:

http://www.eham.net/forums/Elmers/5317

 

[fnkycoldmedina]

i have seen that amp labeled as 321, .have seen them on ebay .if i can track one down i,ll post a picture.

 

[Bionic Chicken]

I see in the thread of the posted link it is a Stam Comm.......I always thought they were made by the same company that built the Snake Charmer wattmeters.......logo looked the same.

 

[Number15]

Looks like a pal 321

 

[paws264]

It is hard to tell from the pics, looks like a Firebird that I have seen.

The keyer circuit is probably that metal can top hat transistor, 2n2905 (guessing from the components around it.) Does the pre-amp still work while in stand-by?

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[skybolt58]

well it was all working, then it started to stop keying, I would just turn the rec on and off and it would work again for a little while... then after doing that for a few weeks , the rec and the tx don't work any more. the tubes all still light up they are 6lx6.. but I broke one the other day pulling it out.. the relay do not click at all. tried cleaning them, but still no go.

 

[paws264]

Disclaimer: By reading this post and following these directions it is presumed that you have the technical knowledge and common sense enough to not get your azz zapped while trouble shooting and fixing your equipment; if you do, don't blame it on me!

Using the Palomar Skipper 300 schematic:

Start at the input coax and trace the RF input until you come to a 10 pf capacitor, this is the capacitive link to your keyer circuit. On the other side of the capacitor, there is a diode and a choke and a PNP transistor (2n2905). There could be a problem with that circuit.

Also, there is a diode that rectifies the AC to provide the DC to power the relay circuit. That voltage goes through the Standby switch. Make sure that you have 12 volts on both sides of your relay (this show that the power supply is working and that you have continuity through the coil of the relay. No 12 volts means PS is not working or switch is bad.

If, there is 12 volts only on one side of main antenna switch relay then that means that the relay is bad.


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[kenny1971]

I have one of these amps also and I could never find any info on it. Mine has 4 6kd6 tubes and does about 400. Very clean and good sounding amp. Worth fixing !!

 

[regencycb]

Stam Comm Products amp

I see in the thread of the posted link it is a Stam Comm.......I always thought they were made by the same company that built the Snake Charmer wattmeters.......logo looked the same.

Its made by stam comm products Inc. refered to as 321 similar to an LDO 321

Check with maycomm they had some manuals in the past.


RCB

 

[skybolt58]

YUP thats it.. except mine don't have the little legs and original fan, and has the 6lx6 tubes. I wonder what the differance in tubes are? I would love to have it fixed , but there is no one in Central NY that will touch it.

I have one of these amps also and I could never find any info on it. Mine has 4 6kd6 tubes and does about 400. Very clean and good sounding amp. Worth fixing !!

 

[Hawke77]

6LF6 tubes can be used instead of 6LX6 tubes. The 6LX6's were a little beefier and I used to use them to beef up Varmint amps that came with the 6LF6's OEM. Typical improved output was around 20 watts/tube. However, 6LX6's have been very rare for maybe 15 or 20 years. 6LF6's would be easier.

That amp was sold under many different brand names. I always suspected it was a Japanese import that was re-branded by Palomar and others. It was a fairly good amp. Usually they were tubed with 6KD6's, also a good tube. The tube cap clips are smaller and would have to be replaced.

8950s could be used, but that is a bit problematic. The filaments would have to be rewired to the tube sockets. Normally they have 2 tubes in series so each tube gets 6.3 volts to the filament. Rewiring the tube sockets so all filaments are in parallel supplies 12.6 volts to the tubes. A little checking might be in order to make sure some pins aren't grounded that are unused on the 6LF6 but are used on the 8950's.

Most common problem with the keying circuit is the 2n2905 keying transistor. Sometimes a 2n2904 will work, but you would have to figure out the differences in the lead positions.

If you replace the 6lx6's with 6lf6's, replace all the output tubes at the same time. Keep the best 6lx6 for the driver tube.

And be CAREFULL, the tops of those tubes can bite you big time. Turn the amp off and short out the tops of the tubes to the chassis to make sure the power supply caps are discharged first!

Hawke

 

[paws264]

I have one of these amps also and I could never find any info on it.

Mine has 4 6kd6 tubes and does about 400. Very clean and good sounding amp. Worth fixing !!

Kenny, What does your amp do that it should not do or, what doesn't it do that it is supposed to do?


.

 

[skybolt58]

still no go

I got 4 new 6lx6 tubes in it. just put in a new 2n2905 keying transistor, and still nothing, no rec and no transmit, now the rec relay when moved with a pencil dose make the rec work.. but when moving the transmit relay it don't key up?

 

[skybolt58]

Update

Well I replaced the 1n4001 diode and it worked, and was working for a while. now it stopped again.. not the diode again, I think I cooked it? I was putting a receive kit in my general grant, and had it hooked throught the amp. amp wa turned off and in standby, didn't think it would hurt it , but I guess it did.. have no Idea where to start, no pre amp and no tx..