palomar 40,20 input SWR

[1iwilly]

Is there a way to make the 20,40 band on a Palomar 300A have a lower input as it does on the 10-meter band with the input and output trimmers
I was tunning on 20 meters today but my Yaesu ft-890 kept flicking a high SWR light I turned the auto tuner on it kind of helped but made the tuner get hot quickly being SWR was past 3.5 I turned it off and put my MFJ auto tuner in line radio show 1.2 I want to make it work with out having to use extra equipment in line if all possible

 

[Shadetree Mechanic]

I suspect that the tap for 20m can be moved on the tuning coil. Try moving it one wind, one way or the other to see.

Edit: I think that is for the amp output, but you said input. Sorry not much help.

 

[nomadradio]

Here's your problem. The band switch only tunes the plate circuits on the output side of the amplifier. The input is tuned for 11 meters only. Or 10, if you like.

The band selector does not include a section to select a separate input circuit for each band. I really don't think they anticipated anyone actually trying to use the other bands. The band selector was just a fig leaf over the private parts. A way to pretend that it was a legitimate amateur gadget, but without spending any more money than they had to for the pretense. This "loophole" got them off the hook until 1979 when the FCC tightened the rules defining a legal amateur amplifier. That's the year that 10 meters disappeared from the front panel of legal ham linears. FCC said 10 meters is too close to 11 meters. The year that spelled the beginning of the end for Varmints, D&A and Black Cat stuff.

Okay, Maco kept at it by building only on night shift. Feds don't work after 4 pm. Don't know how Wawasee (Black Cat) continued to get away with it after 1979, but they did for a while.

Joe ham is entitled to add that band back to the amplifier after he owns it, but the factory was not permitted to sell it built in a way that worked above 25 MHz.

The D&A Phantom and Maverick amplifiers that have a ham-band selector on the front are the same way. The only tuned input circuit is 10/11 meters only. Same reason. The ham bands are just a pretend feature they didn't expect you to use.

73

 

[1iwilly]

Here's your problem. The band switch only tunes the plate circuits on the output side of the amplifier. The input is tuned for 11 meters only. Or 10, if you like.

The band selector does not include a section to select a separate input circuit for each band. I really don't think they anticipated anyone actually trying to use the other bands. The band selector was just a fig leaf over the private parts. A way to pretend that it was a legitimate amateur gadget, but without spending any more money than they had to for the pretense. This "loophole" got them off the hook until 1979 when the FCC tightened the rules defining a legal amateur amplifier. That's the year that 10 meters disappeared from the front panel of legal ham linears. FCC said 10 meters is too close to 11 meters. The year that spelled the beginning of the end for Varmints, D&A and Black Cat stuff.

Okay, Maco kept at it by building only on night shift. Feds don't work after 4 pm. Don't know how Wawasee (Black Cat) continued to get away with it after 1979, but they did for a while.

Joe ham is entitled to add that band back to the amplifier after he owns it, but the factory was not permitted to sell it built in a way that worked above 25 MHz.

The D&A Phantom and Maverick amplifiers that have a ham-band selector on the front are the same way. The only tuned input circuit is 10/11 meters only. Same reason. The ham bands are just a pretend feature they didn't expect you to use.

73

so without sending it to a shop, it will be cost-effective, and cheaper to buy a ham amp. 300A will be a splatter box on 40,20 ??

 

[Shockwave]

If you don't overdrive it, it won't be a splatter box. However, you will need to use an antenna tuner with it in order to get that input SWR manageable. As long as the output Tunes properly without the load or tune control all the way to one side, it shouldn't be too bad.

 

[doffo]

Here's your problem. The band switch only tunes the plate circuits on the output side of the amplifier. The input is tuned for 11 meters only. Or 10, if you like.

The band selector does not include a section to select a separate input circuit for each band. I really don't think they anticipated anyone actually trying to use the other bands. The band selector was just a fig leaf over the private parts. A way to pretend that it was a legitimate amateur gadget, but without spending any more money than they had to for the pretense. This "loophole" got them off the hook until 1979 when the FCC tightened the rules defining a legal amateur amplifier. That's the year that 10 meters disappeared from the front panel of legal ham linears. FCC said 10 meters is too close to 11 meters. The year that spelled the beginning of the end for Varmints, D&A and Black Cat stuff.

Okay, Maco kept at it by building only on night shift. Feds don't work after 4 pm. Don't know how Wawasee (Black Cat) continued to get away with it after 1979, but they did for a while.

Joe ham is entitled to add that band back to the amplifier after he owns it, but the factory was not permitted to sell it built in a way that worked above 25 MHz.

The D&A Phantom and Maverick amplifiers that have a ham-band selector on the front are the same way. The only tuned input circuit is 10/11 meters only. Same reason. The ham bands are just a pretend feature they didn't expect you to use.

73

That is good information to have. I have a Palomar 350Z from my old man that one day I would like to run again, but if the other bands on it are just for looks, I wouldnt dare try 20 or 40 meter bands. Just to be sure, was this for all the palomar amps out there of the 1970s or not all?

 

[nomadradio]

for all the palomar amps out there

And D&A. Can't remember seeing a band selector on a Maco or a Kris.

I really don't think the manufacturers expected anyone to actually try to use the other ham bands.

There were a few 3-band Phantom amplifiers that had a "band" switch on the rear panel. It would bypass the 11-meter tuned input circuit, and feed drive straight to the four driver tubes. Input-side SWR was really high using the straight-through option, and power would drop.

A fig leaf over the private parts.

73

 

[1iwilly]

If you don't overdrive it, it won't be a splatter box. However, you will need to use an antenna tuner with it in order to get that input SWR manageable. As long as the output Tunes properly without the load or tune control all the way to one side, it shouldn't be too bad.

being that the driver section is not being used. would 40 to 60 watts drive from the radio be considered a safe zone.?? For SSB

 

[Shockwave]

being that the driver section is not being used. would 40 to 60 watts drive from the radio be considered a safe zone.?? For SSB

Yes. That will prevent overdrive.

 

[1iwilly]

Yes. That will prevent overdrive.

Thanks, Shockwave

 

[1iwilly]

Here is an update my OCD and Marine attitude would not take defeat after a phone call this morning I fixed my problem the trimmer shown in the picture took care of my input best I can get is 1.4 from almost 2.8

 

[nomadradio]

Cool! A white face, looks like.

If the relays give you trouble, maybe we'll have production stock for the plug-in relay board by then. Demand for that item has been, shall we say, modest so far.

If the preamp still works, just don't flip the SSB switch when the preamp is turned on. Makes it last longer.

And if the preamp is dead, no surprise. Biggest reason we don't include it in my replacement relay board.

High side is genuinely "hot-rod" mode. It's a lot less likely to slide off of a tight curve and wrap around a tree using Low side.

73