rps@sunman.mlb.semi.harris.com (Ray Sumperyl) (04/09/91)
Can anybody supply me with a schematic for a tube TRF receiver?
Regards,
Ray S
rps@sunman.mlb.semi.harris.comwhit@milton.u.washington.edu (John Whitmore) (04/10/91)
In article <1991Apr9.124118.27031@mlb.semi.harris.com> rps@sunman.mlb.semi.harris.com (Ray Sumperyl) writes: > Can anybody supply me with a schematic for a tube TRF receiver? No such devices have been built by THAT name in most of a century. Any of the '60s vintage Radio Amateur Handbooks, though, will have 'grid-dip meter' construction articles, and a grid dip meter is exactly a TRF receiver (not terribly sensitive, though, as they usually leave out the preamplification). After mid-60's, the grid-dip meters used MOSFETs (what's a 'grid' in a MOSFET?). John Whitmore
brian@ucsd.Edu (Brian Kantor) (04/10/91)
In article <1991Apr9.220744.4049@milton.u.washington.edu> whit@milton.u.washington.edu (John Whitmore) writes: > No such devices have been built by THAT name in most of >a century. I beg to differ, grasshopper. I built a TRF in junior high school, the Philco and Atwater-Kent radios were TRFs for a while, and even old grandpop built them when he was working for Lee DeForest - out of triode valves he built himself, yessindeed. Half a century, maybe. This isn't 2030 yet, not by a long row of trees. - Brian (in old fart mode)
stealth@caen.engin.umich.edu (Mike Pelletier) (04/11/91)
In article <1991Apr9.220744.4049@milton.u.washington.edu> whit@milton.u.washington.edu (John Whitmore) writes: >In article <1991Apr9.124118.27031@mlb.semi.harris.com> rps@sunman.mlb.semi.harris.com (Ray Sumperyl) writes: > >> Can anybody supply me with a schematic for a tube TRF receiver? > > No such devices have been built by THAT name in most of [...] Could you, Mr. Whitmore, please refrain from crossposting your article to all of rec.radio, and could you, Mr. Sumperyl, take a look at what groups you`re following up to and modify them so that they're appropriate? I mean really, who in rec.radio.cb would have a schematic for a tube TRF reciever? And why in misc.forsale, let alone rec.radio.cb?? -- Mike Pelletier | The University of Michigan's | [this section intentionally] Computer Aided Engineering Network | [ left blank ] Usenet, UUCP, IRC and mail admin |
fiesta@cbnewsi.att.com (eric.c.beck) (04/11/91)
> Can anybody supply me with a schematic for a tube TRF receiver?
There's an outfit called Lindsay Books in Illinois that sells lots of
vintage books. They've got two catalogs, one focusing on machine and engines,
and the second on electronics. Get the catalog for "old-time" electronics
books - I'm sure you'll find something in there that is exactly what you need.
Eric Beck
jfw@ksr.com (John F. Woods) (04/12/91)
In <1991Apr9.220744.4049@milton.u.washington.edu> whit@milton.u.washington.edu (John Whitmore) writes: >In article <1991Apr9.124118.27031@mlb.semi.harris.com> rps@sunman.mlb.semi.harris.com (Ray Sumperyl) writes: >> Can anybody supply me with a schematic for a tube TRF receiver? > No such devices have been built by THAT name in most of a century. >Any of the '60s vintage Radio Amateur Handbooks, though, will have 'grid-dip >meter' construction articles, and a grid dip meter is exactly a TRF receiver >(not terribly sensitive, though, as they usually leave out the >preamplification). After mid-60's, the grid-dip meters used MOSFETs (what's >a 'grid' in a MOSFET?). Well, in fact the 1963 Radio Amateur's Handbook has schematics for single-stage tube TRF receivers; you would just build a detector stage (plate detector, infinite impedance detector, or grid-leak detector) and wire the antenna to the RF input. You could then add an RF amplifier, if you wanted, remembering not to cheat and do any conversion stages ;-). As for no one building a TRF receiver in most of a century, check out the Ferranti ZN414 AM Receiver chip (available from Circuit Specialists and a couple of other places). It's a 10 transistor TRF receiver (4 amplifier stages, detector, and AGC) built into a TO-92 transistor package; add two resistors, two bypass capacitors, an LC tank, and an audio amp, and you have a complete receiver. (The 1963 Handbook also has a 110 page advertisement section that will make you CRY -- MAYBE a quarter of the advertisers still exist)
whit@milton.u.washington.edu (John Whitmore) (04/12/91)
In article <3106@ksr.com> jfw@ksr.com (John F. Woods) writes: >In <1991Apr9.220744.4049@milton.u.washington.edu> whit@milton.u.washington.edu (John Whitmore) writes: >>In article <1991Apr9.124118.27031@mlb.semi.harris.com> rps@sunman.mlb.semi.harris.com (Ray Sumperyl) writes: >>> Can anybody supply me with a schematic for a tube TRF receiver? >> No such devices have been built by THAT name in most of a century. >As for no one building a TRF receiver in most of a century, check out the >Ferranti ZN414 AM Receiver chip Okay, I guess I was a little strong on that statement; what I really meant was that TRF receivers usually show up as little glue components (like in a garage door opener) rather than as a 'receiver'. Yes, there IS a place for tuned RF receivers, but conversion is the norm nowadays (and has been for quite a few years). TRF works best at low frequency (where the Q of an LC circuit offers adequate selectivity), and its only real advantage (cost) has rather been taken away by the cheap ceramic IF filters in use nowadays. John Whitmore