Palomar Elite 225 10 Meter Mod - 2 Resistors?

[Wire Weasel]

Does a new Palomar Elite 225 have two big 5 watt resistors in them, right next to each other, when removed or disconnected, allow 10 meter operation?

This is from another thread I started yesterday in the Tech forum. Friend brought the amp by and show me the "loose" parts he saw and thought they were diodes. They appear intentionally unsoldered (1 leg) and left in place. The board area around the resistors does not look discolored from any overheating nor are any other nearby components affected.

He was looking around inside because the amp is recently doing around 20 watts or so less than it has been and he was just fishing for problems.

So I don't think anything is wrong, maybe the pills are just beginning to get slightly weaker with age. Amp otherwise still works good and sounds clean and clear.

So does this amp require a 10 meter mod via two resistors?

Thanks

 

[BOOTY MONSTER]

Genuine Palomar 225 LINEAR Amplifier

its supposed to cover 26-30 MHz. as is .

On/Off Power
200 Watt PEP*
TX/low-med-hi
(2) SD1446/MP
13.8 VDC/Nom.
26-30 Megahertz
Receiver Pre-Amp
Auto SSB Switching
Fused/Internal 20Amp
5 Pole Chebyshev Filter
Vhf Stripline Construction
Drive Controlled AB1/2 Bias
Pwr, Tx and Preamp Indicators
Suitable for ISM Applications

 

[9C1Driver]

That amp will cover both 10 & 11m right out of the box like Booty just said. There is no mod or conversion. Sounds like something might need fixed.

 

[Moleculo]

A picture would help.


27 & 28 mhz are so close to each other most of these amps will cover it no problem.

 

[GLR]

Palomar 225 is what the specs BOOTY gave were for but to my knowledge that was never called "ELITE". Is this a black face or blue face amplifier?

 

[Wire Weasel]

It's the blue. I'll reconnect the resistors and see what happens. Will probably fix it. Can't hurt anything....the place they "came loose" from is obviously where they go.

Thanks aeverybody

 

[Wire Weasel]

Update. Resistors reconnected and all is well. Must have popped out from current/heat flowing through them. I didn't figure that heat radiating off the pills did it.

I was not impressed with the tiny little solder-ring surface on the solder side of the board that the components solder to. Guess was done en masse with wave soldering at the factory. Seemed very little surface area for a solder connection seeing as its a relatively high current device.

Whole board was fairly easy removal from heat sink body. Had a choice of desoldering two large grounding tabs going to the SO 259 and the two SO 259 center conductors; or what I chose was; the SO's were connected to the body with two aluminum rivets. So I drilled out the rivets and reconnected when done with screws & nuts. Didn't have to desolder anything. Also makes it real easy to take apart for any next-times.

Thanks for the tips everyone

 

[9C1Driver]

Cool deal, good job.

 

[BOOTY MONSTER]

a bit late , but sorry for the wrong info , for some reason i didnt notice "Elite" .

 

[mackmobile43]

Update. Resistors reconnected and all is well. Must have popped out from current/heat flowing through them. I didn't figure that heat radiating off the pills did it.

I was not impressed with the tiny little solder-ring surface on the solder side of the board that the components solder to. Guess was done en masse with wave soldering at the factory. Seemed very little surface area for a solder connection seeing as its a relatively high current device.

Whole board was fairly easy removal from heat sink body. Had a choice of desoldering two large grounding tabs going to the SO 259 and the two SO 259 center conductors; or what I chose was; the SO's were connected to the body with two aluminum rivets. So I drilled out the rivets and reconnected when done with screws & nuts. Didn't have to desolder anything. Also makes it real easy to take apart for any next-times.

Thanks for the tips everyone

Those amps and many others do have over/heating issues that do cause parts to de/solder themselves which is easily cured by the installation of a fan on the heat sink.

 

[TXRiverRat]

I'm thinking about picking up a good Palomar 225. Any suggestions on availability? I see a couple available on Ebay around low $100s, but I'm not certain of their operational condition.

I did pick up a HYS TC-300N (new). It's showing over 100W on Low and just over 200W on High, haven't tried SSB yet, sent my other radios out for tweeking. My current old Midland 23 chl is showing about 6-7watts output.

 

[nomadradio]

Most small amplifiers will require the radio's carrier power be set at 3 Watts or less. Sometimes a lot less.

A High/Low/Medium switch on the front will allow the amplifier to cope with a higher carrier drive, set to medium or low. Too much carrier reduces the audio level they hear at the other end. Can make the amplifier run hot, to boot.

Amplifiers are not all created equal. And the 'sweet spot' for carrier power won't be the same for all amplifiers.

Beware installing "variable key" in a 23-channel radio. Some of them just don't respond well to it.

73

 

[TXRiverRat]

Most small amplifiers will require the radio's carrier power be set at 3 Watts or less. Sometimes a lot less.

A High/Low/Medium switch on the front will allow the amplifier to cope with a higher carrier drive, set to medium or low. Too much carrier reduces the audio level they hear at the other end. Can make the amplifier run hot, to boot.

Amplifiers are not all created equal. And the 'sweet spot' for carrier power won't be the same for all amplifiers.

Beware installing "variable key" in a 23-channel radio. Some of them just don't respond well to it.

73

Thanks for the info.