Single or Double Converstion???
10-11-2007 | 09:20 PM
#1
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From: Toronto,
ON, CANADA
Single or Double Converstion???
What is the difference between single and double conversion, what does it pertain to, and which one should i use with a JR X-378 transmitter??
Thanks
Thanks
10-11-2007 | 09:33 PM
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From: Tracy,
CA
RE: Single or Double Converstion???
Which type of crystal to use is related to your receiver only. The transmitter uses the same crystal for that specific frequency - no change there.
The single or double conversion difference depends on the circuitry within the receiver, and which type it needs. The receiver should say, right on top.
By the way, get a JR crystal for a JR receiver, Hitec crystal for a Hitec receiver, etcetera. Some of the crystals can be used in different receivers, but many of the guys at the LHS don't know, so just get the same brand and be done with the issue.
The single or double conversion difference depends on the circuitry within the receiver, and which type it needs. The receiver should say, right on top.
By the way, get a JR crystal for a JR receiver, Hitec crystal for a Hitec receiver, etcetera. Some of the crystals can be used in different receivers, but many of the guys at the LHS don't know, so just get the same brand and be done with the issue.
10-12-2007 | 02:39 PM
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From: Garland, TX
RE: Single or Double Converstion???
I'm not sure there is a definite answer when it comes to "which is better":
It depends......
Or, neither is better, they're just different......
Futaba and Hitec tend to use single conversion for their short range receivers and dual conversion for the full range models.
Many JR receivers are single conversion, even expensive 10 channel models (like the R2100 @ $189.99).
It depends......
Or, neither is better, they're just different......
Futaba and Hitec tend to use single conversion for their short range receivers and dual conversion for the full range models.
Many JR receivers are single conversion, even expensive 10 channel models (like the R2100 @ $189.99).
10-12-2007 | 02:45 PM
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From: Emmaus,
PA
RE: Single or Double Converstion???
Just make sure it is listed as a "Full Range" receiver for nitro aircraft (and for park flyers if you want the best performance). Probably best to stick with name brands, Futaba, Hitec, JR, Berg, Hobbico, Tower, etc. I quit using the "park flyer" or "limited range" receivers in my park flyers and foamies, I got too much glitching with them when flying with other guys. There are plenty of "micro" size full range receivers to choose from if you want a good RX for park flyers and foamies.
10-12-2007 | 02:47 PM
#6
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RE: Single or Double Converstion???
RCU has a pretty good forum dedicated to radio topics. And there is a thread over there that was started the day before this one on this very topic. Interesting answers there. More technical than might be posted in a beginners forum but good.
http://www.rcuniverse.com/forum/m_6478901/tm.htm
http://www.rcuniverse.com/forum/m_6478901/tm.htm
10-12-2007 | 02:51 PM
#7
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RE: Single or Double Converstion???
ORIGINAL: RedGN
Is one better than the other, meaning is single conversion better than double conversion or vise versa.
Is one better than the other, meaning is single conversion better than double conversion or vise versa.
I'd say that when a mfg uses the terms in his entire line of RXs, he's telling you that he makes single conversions with lower standards than for his double conversion RXs.
And if you see a RX that doesn't say "conversion" anywhere, it's because it doesn't matter with that RX from that mfg.
10-13-2007 | 08:15 AM
#8
Senior Member
RE: Single or Double Converstion???
Here is a perfect example of why the term "conversion" means so little and can actually confuse our decision when shopping for RXs.
Do you see the term used anywhere in the description of this RX?
But read what it says about the receiver's range.
Do you see the term used anywhere in the description of this RX?
But read what it says about the receiver's range.
This is the Berg Microstamp 4L 4 Channel FM Micro Receiver from
Castle Creations.
FEATURES: Small and lightweight design yet still yields solid performance in
harsh indoor RF environments, ParkFlying, or even at the flying
field in your nitro powered models.
Delivers full range so it is perfect for any 4-channel operation from
small indoor electric models to full-blown glow powered models
Auto detecting Positive or Negative Shift polarity
Fail safe (programable ON and OFF) upon 2 seconds of no signal,servos
move and hold to pre-programmed positions until signal returns
Hold Mode (programable ON and OFF) all servos are held in positions
of last known good signal before signal loss until signal returns
INCLUDES: One Microstamp 4 channel receiver
Two jumpers (used to program Fail Safe, Hold Mode & other operations)
One Castle Creations logo decal
REQUIRES: Castle Creations Berg Micro Crystals (CSEL01**)
SPECS: Length: 1.35" (34mm)
Width: .60" (16mm)
Height: .35" (9mm)
Weight: .14oz (4 grams) with wires
Antenna wire length: 38" (965mm)
Filtering: Triple tuned RF circuitry. Steep Flank 8-pole IF ceramic
filter. True DSP Filtering in the microprocessor decoder with
adaptive algorithms based on signal/noise ratio of the received
signal Sensitivity: about 2.0uV
Castle Creations.
FEATURES: Small and lightweight design yet still yields solid performance in
harsh indoor RF environments, ParkFlying, or even at the flying
field in your nitro powered models.
Delivers full range so it is perfect for any 4-channel operation from
small indoor electric models to full-blown glow powered models
Auto detecting Positive or Negative Shift polarity
Fail safe (programable ON and OFF) upon 2 seconds of no signal,servos
move and hold to pre-programmed positions until signal returns
Hold Mode (programable ON and OFF) all servos are held in positions
of last known good signal before signal loss until signal returns
INCLUDES: One Microstamp 4 channel receiver
Two jumpers (used to program Fail Safe, Hold Mode & other operations)
One Castle Creations logo decal
REQUIRES: Castle Creations Berg Micro Crystals (CSEL01**)
SPECS: Length: 1.35" (34mm)
Width: .60" (16mm)
Height: .35" (9mm)
Weight: .14oz (4 grams) with wires
Antenna wire length: 38" (965mm)
Filtering: Triple tuned RF circuitry. Steep Flank 8-pole IF ceramic
filter. True DSP Filtering in the microprocessor decoder with
adaptive algorithms based on signal/noise ratio of the received
signal Sensitivity: about 2.0uV
10-13-2007 | 08:31 AM
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From: Emmaus,
PA
RE: Single or Double Converstion???
Manufacturers like Berg and JR probably don't like to label their RXs as single-conversion because most people assume it's inferior. JR, Berg, and even Hitec make full range RXs that are single conversion, Hitec is the only one that labels it as single conversion (the Mini-6S).
In general, single conversion requires much better filters than dual conversion, but either architecture can yield a good full range receiver.
In general, single conversion requires much better filters than dual conversion, but either architecture can yield a good full range receiver.
10-13-2007 | 01:18 PM
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From: Poolesville, MD
RE: Single or Double Converstion???
ORIGINAL: da Rock
than for his double conversion RXs.
And if you see a RX that doesn't say "conversion" anywhere, it's because it doesn't matter with that RX from that mfg.
than for his double conversion RXs.
And if you see a RX that doesn't say "conversion" anywhere, it's because it doesn't matter with that RX from that mfg.
But be careful with that one...
If there is no specification as to the expected range, leaving out anything about filtering and conversion in the advertizing, TENDS to indicate that you are looking at a receiver not suitable for larger/better planes.
Manufactureres are quick to point out better specs, interference filtering and longer ranges.
---
FYI: Our flying field is surrounded by interference sources... WiFi, Pager Towers, Power Lines, etc.
I have no problem flying with RX's touted as being "dual conversion", "long range tripple filtered ( what does this mean? )", etc.
If I switch to Single Conversion Micro receivers on the same frequency, OH BOY... Glitch, glitch, glitch... crash... even when close in... without fail no matter the brand...
Scanners of course pick up nothing.
10-13-2007 | 02:02 PM
#11
Senior Member
RE: Single or Double Converstion???
ORIGINAL: opjose
But be careful with that one...
If there is no specification as to the expected range, leaving out anything about filtering and conversion in the advertizing, TENDS to indicate that you are looking at a receiver not suitable for larger/better planes.
Manufactureres are quick to point out better specs, interference filtering and longer ranges.
---
FYI: Our flying field is surrounded by interference sources... WiFi, Pager Towers, Power Lines, etc.
I have no problem flying with RX's touted as being "dual conversion", "long range tripple filtered ( what does this mean? )", etc.
If I switch to Single Conversion Micro receivers on the same frequency, OH BOY... Glitch, glitch, glitch... crash... even when close in... without fail no matter the brand...
Scanners of course pick up nothing.
ORIGINAL: da Rock
than for his double conversion RXs.
And if you see a RX that doesn't say "conversion" anywhere, it's because it doesn't matter with that RX from that mfg.
than for his double conversion RXs.
And if you see a RX that doesn't say "conversion" anywhere, it's because it doesn't matter with that RX from that mfg.
But be careful with that one...
If there is no specification as to the expected range, leaving out anything about filtering and conversion in the advertizing, TENDS to indicate that you are looking at a receiver not suitable for larger/better planes.
Manufactureres are quick to point out better specs, interference filtering and longer ranges.
---
FYI: Our flying field is surrounded by interference sources... WiFi, Pager Towers, Power Lines, etc.
I have no problem flying with RX's touted as being "dual conversion", "long range tripple filtered ( what does this mean? )", etc.
If I switch to Single Conversion Micro receivers on the same frequency, OH BOY... Glitch, glitch, glitch... crash... even when close in... without fail no matter the brand...
Scanners of course pick up nothing.
So when you're switching to a RX that's labeled as "single conversion", it wouldn't be to one of theirs as they don't use the term. You would have to be switching to a RX manufactured by a company who uses the term and uses it in their labels as single or double to inform you of the quality of THEIR two different types of RXs.
The problems a lot of beginners and seasoned modelers have is confusing the concept with the label, or more exactly, the misunderstanding of the concept because of Futaba's use of it as a label.
10-13-2007 | 08:20 PM
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From: Poolesville, MD
RE: Single or Double Converstion???
ORIGINAL: da Rock
Be careful......... Because the following is very true: Manufacturers like Berg and JR probably don't like to label their RXs as single-conversion because most people assume it's inferior. JR, Berg, and even Hitec make full range RXs that are single conversion,
Be careful......... Because the following is very true: Manufacturers like Berg and JR probably don't like to label their RXs as single-conversion because most people assume it's inferior. JR, Berg, and even Hitec make full range RXs that are single conversion,
They just use a different filtering scheme that seems effective.
JR doesn't call the R6UL ( Micro ) receiver single conversion either, but I've found that it is most prone to problems at our field...
Typical obfuscation... it's hard as a buyer at times to figure out exactly what we are getting.
10-14-2007 | 06:37 AM
#13
Senior Member
RE: Single or Double Converstion???
ORIGINAL: opjose
And at least in the case of JR RX's -ALL- of the JR "long range" receivers ARE single conversion.
They just use a different filtering scheme that seems effective.
JR doesn't call the R6UL ( Micro ) receiver single conversion either, but I've found that it is most prone to problems at our field...
Typical obfuscation... it's hard as a buyer at times to figure out exactly what we are getting.
ORIGINAL: da Rock
Be careful......... Because the following is very true: Manufacturers like Berg and JR probably don't like to label their RXs as single-conversion because most people assume it's inferior. JR, Berg, and even Hitec make full range RXs that are single conversion,
Be careful......... Because the following is very true: Manufacturers like Berg and JR probably don't like to label their RXs as single-conversion because most people assume it's inferior. JR, Berg, and even Hitec make full range RXs that are single conversion,
They just use a different filtering scheme that seems effective.
JR doesn't call the R6UL ( Micro ) receiver single conversion either, but I've found that it is most prone to problems at our field...
Typical obfuscation... it's hard as a buyer at times to figure out exactly what we are getting.
Absolutely !
And what screws up lots of our judgements being universally applicable, are things like how the JR R610UL works at other fields. It's almost 100% of the RXs you see at some glider fields because it's long range performance thumps the competition and they aren't seeing the kind of interference your field must be seeing. I've got them in all my gliders and not even a hint of problems. http://www.horizonhobby.com/Products...ID=JRPR610UL**
BTW, good to see someone FINALLY understand the complexity of my point. thanks
