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Author Topic: c crane ep pro  (Read 615 times)
K1QQQ
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Posts: 165




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« on: September 20, 2018, 11:22:55 PM »

Anybody have the new C Crane EP-PRO ?

I just want to confirm quirks (a word?) while in warranty.


On tuning AM the stations seem a little broad at first and #1 oddity is you do not hear the station at first but have to wait a short while to hear.  It makes it kind of hard to tune the analog radio in the 10khz steps fast.


Otherwise it seems to receive my normal weakest stations and lock them in.


Normal DSP radio ?
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SOFAR
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Posts: 1258




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« Reply #1 on: September 21, 2018, 12:59:51 AM »

Here's a review.

https://radiojayallen.com/c-crane-cc-ep-pro-am-fm-analog-tuned-radio/
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RENTON481
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Posts: 239




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« Reply #2 on: September 22, 2018, 08:13:22 AM »

It's the DSP chip inside the radio. If it is a new EP, they no longer have analog IF chips. It's a digital IF chip, a DSP chip that is mechanically tuned through a potentiometer, and it will take a little bit to center in on a station. First, the chip 'finds' the frequency you are tuning to, then the RF amp and DSP chip combined will 'tune' to the signal to maximise it.

It will take a little longer than an analog IF chip tuned radio. I have a Radio Shack Pocket Radio which might have the same DSP chip, or one similar enough to it. You tune slowly to maximise the signal. Soon enough, it sort of 'clicks' in. It's because it's a digital, as opposed to an analog process.

I have read good things about the new CCraneEP's.  I would give it a chance before junking it or returning it.

They went DSP because apparently the analog IF chips they used to put in CCrane analog tuned radios aren't made anymore.
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RENTON481
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Posts: 239




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« Reply #3 on: September 22, 2018, 06:08:49 PM »

PS I don't have the CCraneEP Pro, I am going by what I have experienced using the Pocket Radio, which I believe is set up similarly as pertains to the DSP chip and how it tunes.

You could probably find the datasheet on the DSP chip in question and it will explain how it works.

With my Pocket Radio it almost 'ratchets' across the band when it tunes. It's hard to describe, but it's the digital chip trying to lock in to the frequency and then maximise it. I am guessing that with your radio it may be similar -- but that is just a guess, based on reviews I've read of the CCraneEP Pro and reading the datasheet on the DSP chip that came with the Pocket Radio.

Good luck with the radio.
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KE8WO
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« Reply #4 on: October 06, 2018, 05:17:28 AM »

I have a good Sangean AM/FM that tunes the same way ... takes a fraction of a second for the station to come in. Its same with a few other DSP based radios that I have ... some are more pronounced in this way than others. Bandscanning is certainly much slower than the old style design radios. The trade off is typical better performance at a given price point.
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K1QQQ
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Posts: 165




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« Reply #5 on: October 10, 2018, 04:49:15 PM »

Thanks everybody.


Yep..I think it is just the DSP chip. Gotta wait a little while. Instead of tuning fast the AM Band by 10khz steps you have to wait until it digests a signal and guess you are on a 10khz step.

Otherwise I'd say it is a nice radio. Gets good reviews.
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SWMAN
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« Reply #6 on: October 12, 2018, 04:03:23 AM »

 I have an older Radio Shack DX 440 that does the same thing, it doesn't have a DSP chip. They called it "chuffing "when that happens. The mod is called Anti Chuffing mod. There is an easy mod for that, I did the mod and now it works much better. Not sure if there is one for your radio or not, you might want to check it out.
 Good luck and 73. Jim. W5JJG
« Last Edit: October 12, 2018, 04:16:52 AM by SWMAN » Logged
KAPT4560
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Posts: 508




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« Reply #7 on: October 12, 2018, 05:32:43 AM »

 I agree that it is common for many digital radios to have a soft 'chuff' as they tune across the band. It is the signal sampling as they tune. Some manufacturers try to mute the radio as it tunes, so that the sampling noise isn't too obnoxious. Different radios will exhibit different thresholds of muting. Some threshold levels might even be adjustable.
 
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RENTON481
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Posts: 239




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« Reply #8 on: October 14, 2018, 06:06:02 AM »

I have an older Radio Shack DX 440 that does the same thing, it doesn't have a DSP chip. They called it "chuffing "when that happens. The mod is called Anti Chuffing mod. There is an easy mod for that, I did the mod and now it works much better. Not sure if there is one for your radio or not, you might want to check it out.
 Good luck and 73. Jim. W5JJG

Chuffing on an analog IF chipped radio like the DX440 is a little bit different than the DSP-tuned situation the OP is talking about.

The newer DSP IF chipped radios actually 'ratchet' across the band if analog tuned, or if digitally tuned (where there is a digital readout) they act more like your 440 does. The digitally tuned DSP chips are designed to work with a microprocessor or other digital means of tuning; the 'mechanically tuned' DSP chips are designed to work with a potentiometer. No digital readout required, no microprocessor required to operate the radio, either.

Here is a datasheet for one of the SiLabs mechanically-tuned DSP chips -- I'm certain many others are similar:
https://www.silabs.com/documents/public/data-sheets/Si4820-24-A10.pdf

The application schematic on Page 9 of the PDF shows how the DSP chip is tuned with a potentiometer. Very cool, when you think about it. A minimum amount of parts, and the radios seem to work rather well.
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