View Full Version : Rcvr high/low band crystal
Rebuild
09-23-2006, 11:48 AM
Would it be unwise to use a channel 50 crystal in a dual conversion Futaba receiver originally purchased operating in the low band with a channel 22 crystal installed? Does this de-tune a rcvr also like I have heard can happen when swapping xmtr crystals? :?
ShawnK
09-23-2006, 12:19 PM
Yes.
Rebuild
09-23-2006, 01:10 PM
Thanks.
BarracudaHockey
09-23-2006, 04:15 PM
Yes and no. It will work but you really should have the reciever retuned. If its used, most of the time the tuning will turn up any problems that are better found on the bench than in the air.
PTFlyer
09-25-2006, 03:58 PM
they tune low band to the "center" of the low bands,.......and high band to the center of the high bands.....
Futaba recomends that you don't use low band crystals' in a high band rx or tx..
will they work....sure...but it may cause glitching...I wouldn't do it.......but that may just be me....
BarracudaHockey
09-25-2006, 04:24 PM
It wont cause "glitching" what it "may" do is reduce range.
If I were flying a big old 3 meter sail plane to where I could barely see it, then I'd worry about it, but considering the range we can see a helicopter to fly at....
However the correct way is to have it tuned
DavidH
09-25-2006, 04:39 PM
I have used a ch. 60 crystal in a receiver that was labeled ch 11. Tony Stillman that owns Radio South told me. Range check it, if it range checks OK. Then it is going to work. I have plugged many different channel crystals into the same rx. Never had a problem. I always range check them when I make a change.
David
Rebuild
10-14-2006, 10:00 PM
Just got a Single Conversion, Futaba 146iP rcvr that was on back order. I received a channel 50 crystal to use in it prior to getting the rcvr. The rcvr has a sticker that says high/low on the case and also on the box it came in. Does this mean that it can be used with high or low band crystals? Neither 'high' or 'low' are highlighted to indicate that it is predominately either band. :?
PTFlyer
10-14-2006, 11:30 PM
if you peek inside the case...where the crystal goes in.........if there is a "painted" red dot on the board it is set for high band.......if there is no dot it is set for low band....
that's what futaba says anyway.......
BarracudaHockey
10-15-2006, 07:57 AM
The 146iP, and Futabas current crop of recievers are labeled High<>Low
Means they are center tuned for the entire band and can be used with any channel in the band.
Rebuild
10-16-2006, 01:02 AM
Good deal! Thank you for that bit of info! :D
spork
10-16-2006, 01:17 AM
The 146iP, and Futabas current crop of recievers are labeled High<>Low
Means they are center tuned for the entire band and can be used with any channel in the band.
Right, but as I recall you have to use single conversion crystals on the 146. You can't use the same crystals from your FM RX's.
DavidH
10-16-2006, 09:01 AM
The 146 is a single conversion receiver. Has to use single conversion crystals.
Most of the other Futaba receivers are dual conversion. Have to use Dual Conversion crystals in Dual conversion receivers.
PPM and PCM recievers use the same dual conversion crystals.
I never did worry about the High/Low designations. If I changed frequency in the receiver. I just did a range check to see if the range was still acceptable.
David
BarracudaHockey
10-16-2006, 01:51 PM
The 146iP, and Futabas current crop of recievers are labeled High<>Low
Means they are center tuned for the entire band and can be used with any channel in the band.
Right, but as I recall you have to use single conversion crystals on the 146. You can't use the same crystals from your FM RX's.
Yep thats why I said "channels" instead of "crystals"
:lol:
spork
10-16-2006, 10:59 PM
Yep thats why I said "channels" instead of "crystals"
I wasn't trying to correct you - just adding some additional info (as it's an easy mistake to make). Of course David's point is correct also. The single-conversion/dual-conversion thing is a completely separate issue from the FM/PCM thing. My statement wasn't really accurate.