Problems with NEW RCI 2970n2..

[fodendaf]

Just checked E-Bay, a matched pair of real Toshiba 2879 finals was 129 bucks. That would probably drive the price of an N2 up 100 bucks.[/QUOTE]
the 2970n2 doesnt use 2sc2879, it uses irf520n to220 style which you can clearly see in the pic above. afaik only the 69ffc4 uses 2sc2879 and i doubt very many of those even sold.

 

[9C1Driver]

Yes I understand that. I was referring to the part about he did not believe the supply of 2879 finals has dried up. This was in part why RCI went to mosfets. If they still made a 2970 with 2879's it would be a very expensive radio until every last one was used up.

 

[Jason Everding]

I just got my brand new 2970n2. Upon opening the box I saw a small screw wedged in between the foam and the cardboard. I opened it up, installed the e-chip, turned the radio on and attempted to key down into a dummy load. The radio at first would not key up. I thought the mic was bad so I grabbed my 14yr old 2950dx's mic. No keydown neither!

I ended up looking at the mic plug terminal inside the radio and noticed a cable was disconnected. Opened up my 2950dx radio to see which was it was supposed to be conected. I cinnected it and now it keys down....whewwwwwwww!

SO, before ordering the radio I read at Bells CB that "ranger radios come with blemishes....dings, etc...) Its true, my brand new, made in malaysia, radio does not look as good as my 14yr old 2950dx made in taiwan!

After so many things going wrong, I want to align this thing myself.....

Could someone please tell me the adjustment point for the driver and finals? is it vr11?

Thanks!

 

[Jason Everding]

I have an RCI 2970N2. Recently it developed a problem. After transmission and mic is un-keyed the radio continues to draw 35+amps. To stop the power draw I have to cycle the power supply power and radio works normal until another transmission is complete and stock mic is un-keyed. Any ideas on the problem?

 

[999]

It sounds like it's going into oscillation and keeping the relay engaged. There could be an issue with the amp board, or it may not like your antenna system. It might be something as simple as changing a jumper, but then again, it might be that deep, dark rabbit hole.

 

[Jason Everding]

Ok thank you

 

[Edd200sx]

Anyone know the value of those smd caps on the feedback boards? I’m going to make my own boards. The resistor is probably 68ohm 2w at a guess

 

[BayouRadioAmplifier]

the EPAC40010A board the board with the 8 IRF520's
shows a feed back circuit with a 2W 100 ohm resistor in
series with a .01 mfd. capacitor. 4 of these.

you could just solder these parts in place.

CB Tricks has this diagram on the DX 98VHP page.

I have worked on a 2970N2 here. still not working.
found a problem with the bias circuit on first IRF520.
I have a post here on it.

also for the final amp, I would set the bias differently.
just setting to 4 volts gate voltage is probably too high.
watch the input current to the radio, and adjust each side
of the PA for about 200 mA current.

 

[BayouRadioAmplifier]

I found this bias problem on this 2970N2
I have here. but radio is still not transmitting fully.

https://www.worldwidedx.com/threads/rci-2970n2-2950-irf520-bias-problem-repair.264585/#post-794662

 

[Edd200sx]

the EPAC40010A board the board with the 8 IRF520's
shows a feed back circuit with a 2W 100 ohm resistor in
series with a .01 mfd. capacitor. 4 of these.

you could just solder these parts in place.

CB Tricks has this diagram on the DX 98VHP page.

I have worked on a 2970N2 here. still not working.
found a problem with the bias circuit on first IRF520.
I have a post here on it.

also for the final amp, I would set the bias differently.
just setting to 4 volts gate voltage is probably too high.
watch the input current to the radio, and adjust each side
of the PA for about 200 mA current.

I Set 520’s at around 3.6v gate. I test first in dca pro to get the switch on but 3.6v is usually ok.

Thanks for the info I’ll check cb tricks as well and make up some feedback boards.