I have found several places on net saying it is better to replace Ceramic disk with Silver mica of the same value.  There reasoning was the Silver mica are far more stable. If this is true is there a time you would not do this. I am doing a 100% rebuild of my TL-922A. replacing all resistors with metal film. But if i can use silver mica to replace the Ceramic Disk I will.

Now the Big Question. I can not find any metal film 47 k ohm 7 watt resistors to go across the caps. I have looked for any thing from 30K ohm to 50 K ohm. Also no luck on the(3) 3 watt 2.66 Meg ohm resistors on the rectifier board.   anyone have any ideas.?

Measuring the high voltage plate on RF amplifiers.

How can you measure the plate voltage on a amplifier?

I looked at some HV probes that can be used with multimeters, but there seems to be a problem with them handling the current. So what to do to accomplish this.

This is what I have looked at.

FLUKE 80K-6 HIGH VOLTAGE PROBE for MULTI-METER METERS!

http://www.tequipment.net/Fluke80K-6.html

What is the voltage rating on the 0.01uF ceramic disk capacitors in the rectifier board on the Kenwood TL-922A?

All of my Caps in my Kenwood amplifier are 500V at 200uF, total of 8 thats 25uF when done. if I change them to 500 V at 350uF that will give me 43.75uF when done. Will I benefit any from that? The amp was made in 1992 and I just want to change them out to be safe.

Wait a few weeks and consider the brand new Kenwood TS-590.

How do you decode the date from the Icom pro series serial number?

I am thinking about getting an oscilloscope for my shack just to tinker with old ham equipment, and to restore some older rigs just for fun. So is a 100 MHz scope good enough. And what is the purpose of duel trace?
The last scope I used was around 1980 and then the scope was probably 10 to 15 years old at that time.
 I asked the same question on QRZ and got a mixed answer. Some said 20 MHz was good enough. some said I need at least a 100 MHz. Others said 350 MHz. I just need more input before spending hard earned money and, I want to get something that is worth having.

Go for the Kenwood TL-922 A. it will max out at about 1300 watts in the SSB mode, and 900 to 1000 in the CW mode. I almost always run mine in the CW mode. The CW/SSB switch just determines the plate voltage 2100 V CW and 3100 V SSB. The switch does not mean you must run CW in one and phone in the other. A new amp that uses “2” 3-500Z tube will run around $3000.00 and up, depending on brand of amplifier. There is nothing wrong with the 811-H amp. So what you pay for a used Kenwood you could get a new 811-H for just a few dollars more. So to me it would be to buy new or used.

Can a 3-500 tube be used as a direct replacement for a 3-400 with no mods in an amplifier?

Can a 3-500 tube be used as a direct replacement for a 3-400 with no mods in an amplifier?

I got my Extra after 10 days of study.  But I already had a basic knowledge of electronics. I should have taken the test years earlier.

A day late and a Dollar short.

 I think Kenwood has waited too long to introduce a new HF rig. The damage is done. Unless Kenwood gets very aggressive with new HF rigs like they were in the 80’s and 90’S they will never regain the lost ground. I like Kenwood, I have owned them for the last 25+ years.
TS-530, TS-830, TS-430, TS-570, TS-790  Two years ago I bought a Icom 756 Pro and I like it, and I am now thinking about getting a Icom 7600. I never would have strayed from Kenwood if they had not have gone so long without something new and got rid of that god awful ugly TS-2000.  If they have a new rig I will look at it, but with reservation.

I currently have a fan dipole for 160, 80, 40, meters. Would I gain anything to separate them into individually fed dipoles? I have a 5 position remote antenna switch so I will still use one coax. There will be no extra cost involved in separate feed lines.

My prospective on the subject.
 
Nothing electronic can be sold unless the FCC gives some sort of certification. If I remember right, all the supposed amplifiers made at that time were supposed to be used on business band.  Which was between CB and 10 meters?  Later the manufactures of the amplifiers made them where they could be used on 10, 15, 20, and 40 meters to get around the law. They still had to have some sort of FCC approval since now they were supposedly ham amplifiers.  Of course most of them had switchable inputs of 4 watts or 100 watts. With the real intended market of CB radio operators.  Once the FCC put a stop to the production of any amplifiers that would work on 10 meters, it was amazing how all the manufactures of business band amplifiers suddenly lost interest in manufacturing amplifiers. Even there supposed ham amplifiers.  But for legality sake I would think that any of those amps that worked on 10 – 40 meters would still be legal to use for ham radio use.  Most of us would agree that they are not very good amplifiers but, if that is all a ham had to work with. I would not condemn him for using it.

Nothing electronic can be sold unless the FCC gives some sort of certification. If I remember right, all the supposed amplifiers made at that time were supposed to be used on business band.  The only thing legal about them was they cannot be used on CB. Later the manufactures of the amplifiers made them where they could be used on 10, 15, 20, and 40 meters to get around the law. They still had to have some sort of FCC approval since they were supposedly ham amplifiers.  Of course most of them had switchable inputs of 4 watts or 100 watts. With the real intended market of CB radio operators.  Once the FCC put a stop to the production of any amplifiers that would work on 10 meters, it was amazing how all the manufactures of business band amplifiers suddenly lost interest in manufacturing amplifiers. Even there supposed ham amplifiers.  But for legality sake I would think that any of those amps that worked on 10 – 40 meters would still be legal to use for ham radio use.  Most of us would agree that they are not very good amplifiers but, if that is all a ham had to work with. I would not condemn him for using it.