Ranger RCI-2950DX power consumption

[Andy479]

Hey there,
2950DX is one of my most favoured 12-10m radios so far, but I can't get over some of its quirks.
One of the major ones is its power consumption. For 10W on FM (max), it's pulling whopping 6A from 12V supply. While on grid, this may not be an issue, other than handling the extra heat (it gets to 42°C on FM ragchews), but on portable it's total battery killer.
Even on 1W setting it's pulling 4.8A.
I contacted RCI support regarding this, and they said it's within limits.

Is there a way how to reduce the power draw? Maybe lower the bias on the finals?
Portable battery power gets heavy with more amps required. And when hiking, every gram counts.

Thanks,

 

[OldTech03]

One thing to make sure of is the gate voltages on the driver and finals if it's above 3.5 volts that could cause current to rise and of course the regulator could have issues it's just hard to know as it could be a product of more than one issue especially if someone was in it that should not have been.

Oldtech03

 

[Andy479]

One thing to make sure of is the gate voltages on the driver and finals if it's above 3.5 volts that could cause current to rise and of course the regulator could have issues it's just hard to know as it could be a product of more than one issue especially if someone was in it that should not have been.

Oldtech03

Yes, it's sort of typical that used RCIs have been improperly modded by the previous owner, but this is not the case.
My warranty seal is still unbroken, no-one was inside yet.

On SSB, the current draw is around 0.6A with no modulation, only on FM/AM it rises to 4.8A - 6A depending on the power setting.
Various specs sheets lists 6A as "normal", and even the manufacturer confirmed this (see above).
So I assume this is not normal behavior?

 

[Captain Kilowatt]

You got what you got. A radio must be designed for low power in order to operate efficiently on low power. Simply turning the power down results in an even poorer efficiency. A 100 watt HF radio is horribly inefficient when the power is turned down to 10 watts however a radio designed to run only 10 watts can be very efficient. If you want QRP portable then you should start looking at different radios. The Yaesu FT-817 is quite popular in that regard however it is not cheap compared to the 2950 but it is a LOT more however.

 

[Andy479]

You got what you got. A radio must be designed for low power in order to operate efficiently on low power. Simply turning the power down results in an even poorer efficiency. A 100 watt HF radio is horribly inefficient when the power is turned down to 10 watts however a radio designed to run only 10 watts can be very efficient. If you want QRP portable then you should start looking at different radios. The Yaesu FT-817 is quite popular in that regard however it is not cheap compared to the 2950 but it is a LOT more however.

The fun part is 2950DX is operating on 10 watts maximum (on FM/AM). In this regard the finals might be overpowered for the purpose, hence the confusion why such power is required. At 100W PA, that'd be no discussion, but 8-10W FM shouldn't need such power.
Specs for FT-817 sensitivity-wise on 12-10m are a tad worse compared to 2950DX.

 

[Handy Andy]

You raised a statement earlier about "FM and AM" and the word "Bias" along with "Finals".

You're taking a radio that isn't hybrid-ized for such an outing...It's class AB to begin with and although you'd be ok if you "threw in a mod that had a switch" that turned off the bias and made it EXCLUSIVE for FM and AM modes only you have a suitcase full of extra support circuitry for the SSB and CW modes that well, Dual-Sideband Suppressed carrier (FM) and AM no audio - already accomplish... all the support circuitry is dragged along with it.

It's your need for power, the use of a power supply like a Solar Panel array the size of the ISS is what scares the heck out of me...

Wouldn't a Connex or Anytone be a better packing choice? Even President offers tiny Out-Of-Band (oddball) radios what are far more efficient than a boat anchor like the 2950 DX - they can even do echo so if you get trapped, lost or otherwise disabled along the journey, you can annoy the h*ll out of hams and freebanders alike on the airwaves so they have no choice but to send out a foxhunt to help save you.

It just seems odd that you'd take a rock like an RCI 2950 - tie it to you and throw yourself into the woods.

Ok remember the old adage - when running from a bear, wear tennis shoes. It may not help you run any faster from the bear. But, it will help you run faster and stay ahead the fella that didn't.

:+> Andy <+:

 

[Shadetree Mechanic]

Maybe lithium batteries would be a good lightweight alternative to what you are using now?

 

[Andy479]

Maybe lithium batteries would be a good lightweight alternative to what you are using now?

I'm using home brewed pack of 9 NCR18650s, balanced and IR-matched, each 3400mAh, so a total of around 100 Watt-hours (3s3p configuration). This suffice for 1.5-2 hours of TX on FM/AM.
Total weight of such package is 2.5kg, including the RCI, which is not bad.
But the problem starts when I want to pack more radios than just the Ranger.

Wouldn't a Connex or Anytone be a better packing choice? Even President offers tiny Out-Of-Band (oddball) radios what are far more efficient than a boat anchor like the 2950 DX - they can even do echo so if you get trapped, lost or otherwise disabled along the journey, you can annoy the h*ll out of hams and freebanders alike on the airwaves so they have no choice but to send out a foxhunt to help save you.

Yes, it's a bizzare choice to run RCI in the wild. But some of its parameters are hard to find in "more efficient" radios. Frequency stability for instance, and 0.15uV per 10dB SINAD on SSB, 24-32MHz unrestricted, SWR meter and quite efficient noise blanker.

Handhelds such as SY-201 or AE2990 couldn't match the specs by far.
And there are bigger boat anchors out there. RCI by itself is "just" 1.95kg

 

[Handy Andy]

A Noise Blanker in the Woods?

(Now! No! You can bring up those "If an XX were to <exp> in the woods would anyone be able to hear it?" jokes later ...oops)

Hmmm...why need one in that realm - unless the static electricity of the furry creatures rubbing against the rocks and trees are bothering the QSO you're in. You should leave the NB switch off - at least you'd have a fighting chance of identifying the animal by the various and different audible levels static dissipation and act accordingly.

(They also make good lightning detectors - just don't become one and leave a carbon trail as the only evidence you were ever here on this planet...)

I can't help but wonder in you're priming for a "prepper" activity..

Don't worry, nothing wrong with that, just a 2950 seems overkill (oops - AGAIN!)

You say you run on batteries and that brings up the realm of a means to recharge them - again I defer back to the reason why use a device that uses AB biasing let alone it's RX being as close to class A seems a little odd. Handheld - correct, have some limitations but you still need to provide the current needs of those power hungry current-munchers that Ranger - contains.

Care to Sub-in an HR2510? Would a PC-122 with a oddball kit do? Wow - the effort to make this work seems like a trip in the woods for a film shoot - you bring in everyone and an excavator just to make room for the Director and their catering staff to feed all of the Key Grips and placate their gripes....

 

[Andy479]

A Noise Blanker in the Woods?

I take it as a universal boat anchor. ANL is not used in the Woods, usually, but it comes in handy in urban environment.
I'm thinking more towards uBitX after few iterations, after they manage to smooth out the edges, and include AGC, fix RX/TX audio and make it 10W across the whole band.
Then it'd make great substitute for the RCI as far as CW/SSB goes. For FM/AM I have already gotten Midland Alan 42 Multi.
Just need to fix-up that one with more frequency coverage (it's currently locked in PL mode), extend FM deviation and fit in lithium batteries inside (most likely 3s1p).

I can't help but wonder in you're priming for a "prepper" activity..

Preppers aren't that common here in Europe, we embrace the doom that is inevitably coming .

Recharging 100Wh outdoors just from solar panel does take its sweet time though.

Ideally the setup should run like this:
- uBitX for 3.5-30MHz SSB/CW, max. 3A, avg. 0.5A - 1kg
- Alan 42, max 1A - 0.35kg
- EA-150 or equivalent 150W PEP HF amp - 12A - 0.2kg
- industrialPPC NF-F12, 0.1A - 0.1kg

All that powered from 21pcs NCR18650B ~ 250Wh - 1.1kg
Should last quite a while

 

[Handy Andy]

Now I feel better...

You're on the right path <*GROAN*>

 

[MicroWave]

Preppers aren't that common here in Europe, we embrace the doom that is inevitably coming.

Being prepared is good, becoming a prepper is much more like a state of mind.