ICOM-ICA20

[skippydiesel]

Its not a JFET so dont go asking the techs at icom for that. You could request a replacement final RF power transistor for the IC-A20 if you are sure that is what you removed.From what you describe so far it might be the 2SC1947 I described earlier, does the size match?

OK - I am quoting advice from JayCar. One of their staff identified the component. I have googled JFET and some of the photos look just like mine thingy . Unfortunately something that looks the same may have different performance so that why I need to positively ID what I have damaged.

 

 

[skippydiesel]

Here are the requested photos - sorry about the quality.

 

 

 

 

[jetboy]

Your photos show that it is the size of a 2SC1947 and the leads are the same, all 3 are insulated from the casing. this is unusual for most RF transistors in that case style dont have a collector lead insulated, so the outer casing is 'hot'. Icom used the 2SC1947 in most of their Amateur radios in the 70's and '80s and soldered the case to the chassis for heat sink, because the case is not connected to the other leads. It was used in IC-202, IC-502, IC-215, IC-245 and probably IC-211 models to name a few.

 

click on the photo here

 

Semiconductor: 2SC1947 (2SC 1947) - TRANSISTOR SILICON NPN / 35V / 1A / 4W / 175MHz... - UK (GBP)

 

someone on here might be able to look at an IC-A20 to confirm, I tried searching the web so far no luck.

 

Someone at Jaycar thought it was a Jfet but trust me - its not.

 

 

[Phil Perry]

You're right, a Jfet it isn't. But I no longer have a service manual for the A20, if I had to guess, that is ether the pre-driver or final output transistor. . whether it could deliver 5 watts even at 50% duty cycle, I dunno / can't recall..I used to rebuild IC A2s ( previous model ) many years ago at an Icom agent repair centre, but it was just a job. . . I rebuilt the A20 I use years back, from bits. . .being a fiddler and hating to spend money on stuff if it was fixable. . . MOST things are fixable, if you want to spend the time. . .but after having £5K worth of uninsured test gear stolen from my workshop in 1993, I never replaced most of it. I still have a selection of tools, a super quality VSWR / Power meter ( Bird Thruline ) with lots of slugs. . .and a selection of other meters, but without a decent spec-analyser and other associated gear,. . . it's mostly informed guesswork mate.

 

 

[ruffasguts]

Suspect it is semiconductor Q316. Q316 is a. 2SC1947

 

Mick w

 

 

[Phil Perry]

Suspect it is semiconductor Q316. Q316 is a. 2SC1947Mick w

That's a power transistor, part of the PA circuit. Either a driver or final, have not looked up the specs, ( busy at the mo ) to see if it has the capability of delivering 5 watts RF output. . . .I don't normally feck about with circuits / components without a service circuit diagram. Which I lent out ( fatal ) some time ago. . .If you are interested, look up the spec on the device, and see if it delivers 5W at 50% duty cycle, class 'A' or more likely 'AB1' ( more efficiency) on VHF / AM. Midband. ( You already know the frequency area )

 

 

[ruffasguts]

That's a power transistor, part of the PA circuit. Either a driver or final, have not looked up the specs, ( busy at the mo ) to see if it has the capability of delivering 5 watts RF output. . . .I don't normally feck about with circuits / components without a service circuit diagram. Which I lent out ( fatal ) some time ago. . .If you are interested, look up the spec on the device, and see if it delivers 5W at 50% duty cycle, class 'A' or more likely 'AB1' ( more efficiency) on VHF / AM. Midband. ( You already know the frequency area )

That info is from the service manaul

Mick W

 

 

[jetboy]

The final for the ICA20 only delivers 1.5 Watts carrier power, 5 Watts is peak and often used for marketing purposes so if Q316 = 2SC1947 then that will be the correct one. Phil mentions the sort of test gear we normally use when checking these radios, and if it was something like a Microair or Xcom this stuff is essential to get it right - with the A8 / A20 fitting the correct device will be OK but take your time, unsolder the old wires with care and use good heat for short time refitting,.use good old multicore solder the toxic stuff with real lead in it the new RoHS stuff is not suitable. Best get someone who does this sort of work a lot.

 

Best of luck Skippydiesel

 

 

[Phil Perry]

That info is from the service manaulMick W

Thanks Guys ( Ruff + Jet ) I lent out my own service manual some years ago. ( Fatal ! )

 

 

[440032]

Curiosity got the better of me, I went back in to my A20 to see if I could find that thing. There it was, just inside the back cover, not at all buried deep in the guts of the radio like the button cell is. I have no idea how you even got it out, and you are right, the part number spec is not visible, I was sorta hoping I might be able to see what it was for you. Nope!

 

 

[skippydiesel]

My heartfelt thanks to all of you.

 

• Next step?? - Purchase a "Q316 / 2SC1947" Class "AB1"
   
   
   
  
• Second step try and clean out the little fitment holes in the circuit board - two out of the three still have the wire legs/terminals embedded in them.
   
   
   
  
• Third step - reassembly everything.
   
   
   
  
• Forth - turn on & hope
   
   
   
  

 

 

 

 

[Birdseye]

Available on Ebay if you can't source elsewhere. Then find somebody who knows what they are doing to put it in. You might want to get them to rebuild your battery pack at the same time :-)

 

 

[Phil Perry]

My heartfelt thanks to all of you.

 

• Next step?? - Purchase a "Q316 / 2SC1947" Class "AB1"
   
   
   
  
• Second step try and clean out the little fitment holes in the circuit board - two out of the three still have the wire legs/terminals embedded in them.
   
   
   
  
• Third step - reassembly everything.
   
   
   
  
• Forth - turn on & hope
   
   
   
  

One nice thing about the ICA20 Skippy,. .. due to it's size and weight, if it doesn't work as a radio, it makes a Superb Door Stop. :-)

If you're determined to do this,. . .ignore the 'Q316' bit, that just identifies the position of the device in the circuit diagram. Don't worry about the class of operation either. . .you only need the '2SC1947' bit. Fitting the base, collector and emitter legs into the correct holes in the board would be a very smart move too ( ! ). . . :-)

 

 

[skippydiesel]

One nice thing about the ICA20 Skippy,. .. due to it's size and weight, if it doesn't work as a radio, it makes a Superb Door Stop. :-)If you're determined to do this,. . .ignore the 'Q316' bit, that just identifies the position of the device in the circuit diagram. Don't worry about the class of operation either. . .you only need the '2SC1947' bit. Fitting the base, collector and emitter legs into the correct holes in the board would be a very smart move too ( ! ). . . :-)

"Qui audet vincit" & sometimes fails - thanks for the encouraging words and additional info.

Just by consulting with Prof. Google, I have come to the realisation that the Q316 and also the Class AB1 seem to be redundant.

 

Yes I realised I would need to get the orientation correct, or of you will, find the right hole(s). I hope instinct, logic or the possibility of further technical advice may come to my aid.

 

I have yet to settle on an Australian supplier - any preferences?

 

 

[Phil Perry]

"Qui audet vincit" & sometimes fails - thanks for the encouraging words and additional info.Just by consulting with Prof. Google, I have come to the realisation that the Q316 and also the Class AB1 seem to be redundant.

Yes I realised I would need to get the orientation correct, or of you will, find the right hole(s). I hope instinct, logic or the possibility of further technical advice may come to my aid.

 

I have yet to settle on an Australian supplier - any preferences?

Dunno any suppliers in OZ Skip. . . I use RS Components online in the UK, I have no idea if they have an outlet in Australia. but I'm sure you'll find someone on here who will know. . You could message Kyle Communications ( on this forum ) Mark will know. . . since he's in the radio tecchie business.

 

 

[440032]

Getting back to the original question of battery:

 

Yes, readily available. That and many more.

 

Australian Rechargeable Lithium Battery & Lead Acid Batteries

 

 

[Birdseye]

Getting back to the original question of battery:Yes, readily available. That and many more.Australian Rechargeable Lithium Battery & Lead Acid Batteries

 

 

[Yenn]

I looked at that site and they were both NiCad, not lithium. having gone through 2 NiCad batteries with my Icom I would not go near them again

 

 

[skippydiesel]

Getting back to the original question of battery:Yes, readily available. That and many more.Australian Rechargeable Lithium Battery & Lead Acid Batteries

Yep! Have purchased two Ni-MH rechargeable battery packs that suit/fit my radio. In fact it was cheaper to purchase the entire factory made battery pack than it was to purchase the cells for my own assembly/installation.

The problem now is an unforeseen additional cost - the need to purchase a battery charger that is compatible with Ni-MH batteries.

 

 

[Phil Perry]

Yep! Have purchased two Ni-MH rechargeable battery packs that suit/fit my radio. In fact it was cheaper to purchase the entire factory made battery pack than it was to purchase the cells for my own assembly/installation.The problem now is an unforeseen additional cost - the need to purchase a battery charger that is compatible with Ni-MH batteries.

Some Intelligent chargers on this site Skip. . .OK, it's in the UK but there is some useful data on batteries and charging for those who may be interested. I've known Roger and his Son for 24 years, and have used their services a number of times. Have a look. . <Strikalite - the rechargable battery specialists > . I bought my Ni MH pulse charger from them a loooong time ago, after I binned all the Ni Cd batteries I had in 5 portable rigs and switched to Ni mH cells... . .

 

 

[skippydiesel]

Some Intelligent chargers on this site Skip. . .OK, it's in the UK but there is some useful data on batteries and charging for those who may be interested. I've known Roger and his Son for 24 years, and have used their services a number of times. Have a look. . <Strikalite - the rechargable battery specialists > . I bought my Ni MH pulse charger from them a loooong time ago, after I binned all the Ni Cd batteries I had in 5 portable rigs and switched to Ni mH cells... . .

Thanks Phil

 

 

[skippydiesel]

Mark from Kyle Communications has found & supplied a replacement part - Thanks Mark.

 

Now I have to fit it - "clean out' the old holes (two of which still have the wire terminals in) , making sure it is correctly oriented & soldered it in - wish me luck.

 

 

[skippydiesel]

Its true confession time - I have managed to totally trash my fully operational Icom (not counting battery)

 

Soooo anyone interested in acquiring an Icom IC A20  for parts or restoration PLUS two new/unused in the box Ni-MH rechargeable battery packs  to suit and one dud battery pack (that could be brought back to life by fitting new cells)

 

ANYONE ?????

 

 

[Markproa]

Hi Skip, bummer about the epic Icom journey. I can relate to that well. Us fixers win some and lose some but we never seem to learn. I guess the wins are such a buzz we can't help ourselves. I have a IC A20 that is still going strong. What do you want for your 'bits'.

 

Cheers,

 

Mark

 

 

[skippydiesel]

Hi Skip, bummer about the epic Icom journey. I can relate to that well. Us fixers win some and lose some but we never seem to learn. I guess the wins are such a buzz we can't help ourselves. I have a IC A20 that is still going strong. What do you want for your 'bits'.Cheers,

 

Mark

You sound like a fellow traveller in the I can fix anything (not) universe.

I am just going to hold off on the sale for the moment as a fellow UK correspondent has offered a functional  but soon to be illegal, in the UK/Europe, IC A20