TEMPO 2020 DEAD RECEIVER

[KL7OF]

I am hoping someone on the forum might have some experience with this problem....I've got a (new to me) Tempo 2020 that was hooked to a rx antenna while QRO transmitters were being operated.  The rx is dead now.  Does the tempo have a fuse/bulb?  What is the component in the rx front end that frys when overloaded?   I am looking for a manual..Thanks for any help....Steve KL7OF

[KD6VXI]

I am hoping someone on the forum might have some experience with this problem....I've got a (new to me) Tempo 2020 that was hooked to a rx antenna while QRO transmitters were being operated.  The rx is dead now.  Does the tempo have a fuse/bulb?  What is the component in the rx front end that frys when overloaded?   I am looking for a manual..Thanks for any help....Steve KL7OF

I'm not very familiar with that radio, but most have a pair of back to back diodes protecting the front end, if it's solid state.

--Shane

[WA1GFZ]

I bet you took out the Q201 3SK35 RF amp a dual gate mos FET. I bet the crystal calibrator is weak also. Doesn't look like a gate protected mouse fet.

[Ed-VA3ES]

Some dual-gate mosfets are getting hard to find now.   You could probably replace it with a 3SK40, 40673, or even better, a 3N201.

[w3jn]

As I recall there's also an issue with the nylon gears that drive the preselector mechanism cracking.  You should check to make sure that assembly is all in proper alignment.

[KL7OF]

Tnx all for the info....I downloaded the manual, (tnx Mac) and found q201...it has been changed to a 3SK44...How can I test it?  Where can I get a replacement? GFZ...the calibrator puts out a strong tone??? This radio was working OK when It was brought over here and now I'm also having trouble with tx out put....can't get a thing......might be a relay problem....I looked at all the nylon gears in there (there is a bunch of them) and some have cracks around the set screw but all seem to be hanging in  there.  This thing reminds me of the ft 101.......I have very little experience with solid state devices..I've got boxes full of NOS transistors that came in an estate ....mostly 2Nxxx don't see any 3Nxxx....

[Jim KF2SY]

3SK44 Crosses to a NTE222
available at Mouser

http://www.mouser.com/search/refine.aspx?Msid=52600000&Mkw=nte222

Uniden or was it GRE ? used it's brother 3sk45c in the DX300 and DX302 ugh...

73
 

[WA1GFZ]

look at the voltage across the source resistor there should be 4 to 10 ma flowing with the AGC wide open. IF you can manually control the AGC the current should drop as the agc is dialed back. Be careful this fet could be static sensitive. Can you hear the calibrator in the radio? If yes look at the stuff John was talking about. I don't know the radio but when I saw the dual gate mouse fets the first one or the second one may have been fried. My SB303 had a problem like that when I first built it.