Ranger RCI-2995 DX CF issues on FM

I don't have this radio or any hands on experience with it so can only garner information from online manuals/circuitry in an attempt to help.


According to the manual for this radio the SWR meter is self calibrating and this looks like the case from the tandem line circuitry within the radio. (Much better than typical internal SWR/PWR meters fitted to a lot of CB's.) The only real way to confirm the accuracy of this would be to use an external SWR meter to compare it against. Unfortunately some cheaper external meters leave a lot to be desired with cheap strip-line circuitry and could cause more confusion!

There is only one calibration adjustment within the radio and that would be factory set to a 50 ohm standard impedance. If your antenna is not 50 ohm the readings won't be accurate and that would be a common case. So long as your SWR readings are low then I wouldn't worry too much. A lot of Radio Amateurs are happy with a SWR of <=2, (myself included), knowing that this is fine to operate at, (90% or better efficiency), and the 1:1 reading is very 'mythical'.

A 50 ohm dummy load would be the only way to be sure, you should then get accurate power measurements and a SWR as near as dammit to 1.


As far as the FM problems it looks like this radio uses a simple phase detection circuitry method which is great in as far as reducing the typical 'hash' associated with FM reception. Unfortunately if you, (unlikely from a new radio), or the other party, (very likely with older radios and those that have been 'twiddled'), are off frequency then the audio will sound quiet. It might be worth talking to as many different FM contacts as possible to gain some reassurance. For some these less common phase and even Foster Seeley discriminator type circuits can seem very quiet compared to single chip solution FM detector as fitted in many radios.
(I have an old 1970's 2m Yaesu radio with such simpler circuitry that sounds awesome on FM! )


Hopefully someone may pop up who has personal experience of this radio and have something useful to add.

If you really aren't that sure I would have a word with the supplier/manufacturer in case anything is amiss.


I hope that's of some help.

All the best,
Victor

Thank you Victor,

I think the SWR needle cannot calibrate properly after the radio has been expanded to 11 meters and tuned…I don’t really care about this issue since I use a good external meter and my SWR readings are very low across the bands.
As regards to the FM receive, I’ve tried many different local stations and they all sound normal when using my McKinley radio but for some reason the Ranger audio volume needs to to be turned up all the way up for me to hear anything on FM. On the other hand everybody is hearing me perfectly fine and bang on frequency when I transmit on FM…strange. Could it be some blown capacitor?… not likely on receive only?

I wouldn't have thought so, poor old capacitors get the blame for a lot of things especially electrolytics. With a new radio it's highly unlikely.

The McKinley as far as I remember uses a typical one chip FM detector so will sound totally different. (As well as noisier with a no signal scenario.) It's also, due to it's detector a little more forgiving with off frequency FM transmissions.

There is an adjustment for the FM detector mentioned in the Ranger manual, (L4), but I wouldn't go touching that unless confident in your abilities. Is there a 'crackle' when you switch to FM mode at all? Because the only other thing I can think of where they could be a problem is the modulation mode rotary selector switch.


As I said maybe someone else has hands on experience of this radio who can give a little more input especially regards it's FM reception.

I hope you get to the bottom of it and find a solution.

Victor wrote:

I wouldn't have thought so, poor old capacitors get the blame for a lot of things especially electrolytics. With a new radio it's highly unlikely.

The McKinley as far as I remember uses a typical one chip FM detector so will sound totally different. (As well as noisier with a no signal scenario.) It's also, due to it's detector a little more forgiving with off frequency FM transmissions.

There is an adjustment for the FM detector mentioned in the Ranger manual, (L4), but I wouldn't go touching that unless confident in your abilities. Is there a 'crackle' when you switch to FM mode at all? Because the only other thing I can think of where they could be a problem is the modulation mode rotary selector switch.


As I said maybe someone else has hands on experience of this radio who can give a little more input especially regards it's FM reception.

I hope you get to the bottom of it and find a solution.

Since there is a separate RX circuit for FM my guess is you are right. I’m going to have to slowly turn the L4 knob CW or ACW until I get a normal audio FM reception. I had a response from the Ranger tech support and they think the same. Well I will try with very small increments both ways and report back once done

Mark it first or am i too late.

Alan, great minds think alike! My thoughts exactly and no you’re not too late as I haven’t opened the beast yet. I have located L4 though as I took pictures of the board last time I opened it to switch the power supply to 220v

I don't know if you have any manuals for this radio but if it helps any :-


Service Manual Free Download :-

https://elektrotanya.com/ranger_rci-2985dx_rci-2995dx_sm.pdf/download.html


Circuit Diagram Free Download :-

https://elektrotanya.com/ranger_rci2995dx_sch.pdf/download.html



Best of luck with it.

Thank you Victor! I had the service manual but not the circuit diagram. Much appreciated

Cheers & 73!

Victor wrote:

I wouldn't have thought so, poor old capacitors get the blame for a lot of things especially electrolytics. With a new radio it's highly unlikely.

The McKinley as far as I remember uses a typical one chip FM detector so will sound totally different. (As well as noisier with a no signal scenario.) It's also, due to it's detector a little more forgiving with off frequency FM transmissions.

There is an adjustment for the FM detector mentioned in the Ranger manual, (L4), but I wouldn't go touching that unless confident in your abilities. Is there a 'crackle' when you switch to FM mode at all? Because the only other thing I can think of where they could be a problem is the modulation mode rotary selector switch.


As I said maybe someone else has hands on experience of this radio who can give a little more input especially regards it's FM reception.

I hope you get to the bottom of it and find a solution.

Well, I did have to turn that L4 CW almost half a turn and bingo FM rx is now sounding loud and clear. Thank you for your help!

That's great news to hear and glad you got it sorted. 

Enjoy your radio.


All the best,
Victor

Glad you got it sorted out.
From sunny Blackpool lol..

Got a ranger 2950dx from the get go fm recieve was off looked at manual and using a plastic screwdriver altered one of the pots off the top of my head thought it was F4 but L4 sounds about right glad you got it sorted

Got me thinking and i don't remember ever using FM on the 2950@s i had over the years.
Had one of the first one's in the country but only ever used ssb.

I have to admit that I rarely use FM as not many peeps in my area. But as a principle I like my radios to properly do all what they were designed to do. I also operate mostly on SSB although the last few days propagation has been less than ideal so I got bored and it pushed me to fiddle with my L4 pot

I am the same it should work if it has the function.
Been away Friday till today so not missed anything then.
Shame my forehead didn't miss the sun on Friday afternoon while having a few pints of the black stuff burnt just a bit 
I know Victor Egypt and all that i just didn't think it was that strong in Blackpool now stop laughing.