Has anyone tried this and how well does it work?

[King Mudduck]

This application note describes how to substitute a total of three ERF-2030s for the discontinued Mitsubishi 2SC1969, 2SC2312,
and 2SC2166 RF transistors in the Galaxy DX77HML, DX88HL, and DX99V 10 meter transceivers. This application note may
apply to other similar transceivers manufactured by RCI.
The supplying of this information in no way holds EKL Components, or any of its members, responsible or liable for any
damage incurred to person or property. This application note, or any other information, provided by EKL Components is to
be used at YOUR OWN RISK.
Required Parts:
3pc ERF-2030
1pc EN-369DR
1pc EN-369FN
1pc 480K ohm, 1/4 watt Resistor
1pc 33K ohm, 1/4 Resistor
1pc 1500pF Ceramic Disc Capacitor
1pc 100 ohm, 1/4 watt Resistor
Insulated Jumper Wire
1) Remove the 2SC1969 or 2SC2312 at TR43.
2) Remove the 2SC1969 or 2SC2312 at TR56.
3) Remove the 2SC2166 at TR44.
4) Install the ERF-2030’s at TR43, TR56, and TR44. Install ERF-2030’s exactly the same way the 2SC1969/2312 and 2SC2166
were installed, using all the SAME HARDWARE.
5) Install the EN-369DR at TR44. Install this part on the solder side of the PCB. IMPORTANT: Do NOT stress the leads of the
EN-369DR by bending them to aggressively. Bend the leads carefully and make sure that they are as short as possible.
a) Solder the EN-369DR positive lead (marked +) to the gate pin of the ERF-2030 at TR44.
b) Solder the EN-369DR negative lead (unmarked) to the source pin of the ERF-2030 at TR44.
6) Install the EN-369FN at TR43. Install this part on the solder side of the PCB. IMPORTANT: Do NOT stress the leads of the
EN-369FN by bending them to aggressively. Bend the leads carefully and make sure that they are as short as possible.
a) Solder the EN-369FN positive lead (marked +) to the gate pin of the ERF-2030 at TR43.
b) Solder the EN-369FN negative lead (unmarked) to the source pin of the ERF-2030 at TR43.
7) Remove capacitor at C167.
8. Remove the 22μH choke installed from location R216 to L35.
9) Remove the 22μH choke installed from location R271 to L50.
10. Remove 2.2 ohm resistor and ferrite bead installed from R218 to L47.
11) Remove C209.
12) Install 1500pF capacitor at C209.
13) Remove C171.
14) Install jumper wire from the left hole at C208 to the right hole at C171. See illustration below for radio orientation.
15) Remove resistor at R285.
16) Add 100 ohm resistor at R285.
17) Install the 480K ohm resistor from the right pad at L41 to the pad closest to the back of the radio at C175. It will be
easiest to install this part on the solder side of the PCB. See illustration for radio orientation.
18) Install the 33K ohm resistor from the pad (hole) marked R271 to the pad closest to the front of the radio at R272. It will be
easiest to install this part on the solder side of the PCB. See illustration for radio orientation.
The following parts are no longer in the circuit, so they can be removed or left alone - it does not matter.
VR10, VR11, VR20
C173, C210
R270, R271, R215, R217

Any power gains in this?

 

[lords]

If done right and adjusted right yes more watts
avg trans 16-18 watts the ERF-2030 is an 25 watts..
if its a ssb radio good luck its a bit harsh till you get it fine tuned
theres tons of transistors left and well worth the money ...
china is blowing smoke

ERF-2030 in my testing and not saying a bad thing, are not fully stable, I don't care what you do to them..but are usable...

 

[Cheech]

one guy around here has a magnum S3-80 I beleive thats what it is. Anyway has those ERF2030s in it and he has blown them countless times. Ill take a 1969 over one anyday.(not bashing your mod or magnum)

 

[lords]

yes, I do say leave the 1969 in the magnum I get 50 watts!
I'd try a IRF520 if I was to do anything like this...

 

[Switch Kit]

It's all fairly new , you can buy the kit's like on cbtricks that they talk about for some radios , the pep will usually be there but the DK wil be low , it has something to do with volting them in order to acheve the higher DKs on them.I was told that these Mosfets can handle a lot of volts ,less amps but more volts. somewaht equals more power . I've done a few on 25s and 29s , but my results were the same , low DK high audio pep swing. There's a few more changes involved , I pretty much stoped there , but if one wanted to used the kits as is ? they would run a box very nicely. Mosfets seem to have a loud audio quality about them ? Why ? I honestly don't know , they just do. If you look closer on cbtricks they talk about it in more detail. It's new to a lot of people KM , but if you have the time to do it , and you feel it wouldn't be a great lose to you ? Go for it . I personally would hope it worked out for you.

 

[lords]

Thats because a Z diode is across the MOSFET to level it to 20 volts tops and the gain is great, more stable then a bipolar transistor

I still want to do with with a IRF520

 

[KC2OST]

Why even bother? You can find the 1969, 2312, etc all over the place.

Unless you burn a transistor you should just leave it alone.
Nobody is going to notice a few watts.

That is a lot of work for little gain.

 

[lords]

Why even bother? You can find the 1969, 2312, etc all over the place.

Unless you burn a transistor you should just leave it alone.
Nobody is going to notice a few watts.

That is a lot of work for little gain.

sure is

 

[King Mudduck]

The only reason i was thinking about it was because since the original finals are getting hard to find this would be a good upgrade.

 

[thedirtmover]

Personally I think that way of doing a dual final is crap. If done correctly with just replacing the finals to IRF520 you can easily get 40-60. If you replace the driver with a FET you can always get 60 out of it if you build it right. I am not a big fan of the EKL versions of the final upgrades, they just dont seem to produce, especially the version for the Cobra 29s.

 

[speedracer6g]

what driver are you using to run the irf520? i have some irf540 here i was giong to mess with. and since the mosfet likes volting can it be done on the cobra 25 and 29. call me dumb but i here about this volting stuff what exactly is volting and how is it done?