Ranger RCI-6300F Question

[Tweek]

I got hold of an old Ranger 6300F (not the TB, -25, or -150), running a pair of 2312's in the finals, and a 2166 in the driver. It's working fine, pep about 20 watts. I think I remember folks talking about them doing more like 45-50 watts pep, but maybe my memory isn't correct. It's pretty much stock, the board is a EPT690010B. The finals test OK, though I've not sub'd them with anything else to check. Should it be doing more, and if so, wonder what I'm overlooking.

Thanks,
Dave

 

[Tweek]

A little bit of an update..I was looking into this more last night and noticed it's probably making as much dead key as it should. RF power on the board will go up to about 12 watts or so, unmodulated. With the carrier at 3 to 5 watts, it'll make about 20 watts PEP modulated. I sub'd in another PNP modulator for Q54 (2SB745Y), but no change. Still looking...

 

[groundwire]

Its a nice radio, just leave it. If you want more power buy an amplifier

 

[sp5it]

45-50 watts pep possible, but with dual final.
Mike

 

[Tweek]

Its a nice radio, just leave it. If you want more power buy an amplifier

An amp is not a problem, but I see where these were typically doing 40+ pep, trying to figure out why this one doesn't. I did check it with only one final connected at the time, one is doing most of the work, the other has low output. Going to sub in another pair and see what happens.

 

[Tweek]

45-50 watts pep possible, but with dual final.
Mike

Hi Mike, this is a dual final radio.

Tnx
Dave

 

[Tweek]

Another, but unrelated, question. Is anyone aware of an improved modulator over the 2SB745Y used in this radio?

Dave

 

[sp5it]

Hi Mike, this is a dual final radio.

If we talk AM PEP I would do npc-rc on it, but you need a scope to set it properly. For SSB set ALC level, but again, without a scope it's impossible.
Also some 2312 and 2166 need more bias than others, but again without a scope no way to set it linear.
Mike

 

[Tweek]

If we talk AM PEP I would do npc-rc on it, but you need a scope to set it properly. For SSB set ALC level, but again, without a scope it's impossible.
Also some 2312 and 2166 need more bias than others, but again without a scope no way to set it linear.
Mike

Hi Mike,

I have a full shop with everything needed, just never tried to mod this final setup for more power. I found the gain on one of the 2312's is way down, no leaky, but on it's way out. Going to make some changes on the PA. I'll be working on that some more, tonight.

Still wondering about an improvement on the 2SB745Y, seems I read somewhere about a sub for it.

Thanks,
Dave

 

[nomadradio]

There are several. 2SB688 and 2SB827 and TIP36 come to mind. The 2SB subs have slightly-higher current ratings. The TIP36 is rated for a bit less.

To beef up base-station versions of this kind of radio we used a 2SA1301. Has a larger package with more surface area against the heat sink. Carries more heat energy with less temperature rise. And much-higher current/power ratings as well. Making it fit in a mobile could call for creativity.

And a larger mica insulator.

73

 

[Tweek]

There are several. 2SB688 and 2SB827 and TIP36 come to mind. The 2SB subs have slightly-higher current ratings. The TIP36 is rated for a bit less.

To beef up base-station versions of this kind of radio we used a 2SA1301. Has a larger package with more surface area against the heat sink. Carries more heat energy with less temperature rise. And much-higher current/power ratings as well. Making it fit in a mobile could call for creativity.

And a larger mica insulator.

73

Thanks, great info. I felt like there was something to be had there, and was pretty sure someone like you had been there long before me I got started in repairing / modding this stuff back at a couple of shops in the mid-70's. Over the last 35 years or so (until retirement), my "real job" took over and I wasn't into it as much...mostly FM repeater builds and restoration / repairs on older ham rigs in my spare time. When I got more into the 11m stuff a few years ago, I was surprised to see how much things have changed!

Dave

 

[TM86]

To beef up base-station versions of this kind of radio we used a 2SA1301. Has a larger package with more surface area against the heat sink. Carries more heat energy with less temperature rise. And much-higher current/power ratings as well. Making it fit in a mobile could call for creativity.

And a larger mica insulator.

Looks like I'm gonna need a bigger hammer.

 

[sp5it]

Junction temperature of 2SB754Y is 150°C - 302°F. Original part is doing well, changing it just for a change is not needed. Snake oil.
Mike

 

[nomadradio]

We only replace that part when it fails. Using a higher-rated part is just cheap insurance. Having the radio repeat the same failure after we fix it is just bad business. Besides, the higher-rated part is seldom much more expensive than the original. And if beefing up that link in the chain just moves the point of failure down (or up) the line, at least a customer with a repeat failure sees that he has blown out a different part this time. Never underestimate the likelihood of stress from abuse.

73