Hallicrafters R-274 aliax SX-73

[iw5ci]

I am planning to start the restoration of this interesting receiver. Actually i have 2 problems... i have an huge intermodulation from family radio received on 6 mhz (maybe because this radio have an if of 6mhz), and then i have some bands where i receive nothing (only white noise). Has someone restored this rx and can give me some help?
For Sp-600 there is huge documentation but for the Halli counterpart only very few infos.

[w3jn]

It's much easier to work on than the SP-600.

You probably have a local oscillator problem if it's completely dead on some bands.  The turret bandswitch is very easy to get to, unlike the SP-600.  Each band module snaps right out.  I had one where some of the contact fingers were broken, that might be a place to start looking.

Also, every one I've seen has had a bad S-meter - burned out movement.

Good luck, let us know what you find.

[WQ9E]

I restored mine a couple of years ago and I didn't run into any unusual problems.  It is single conversion on the lower bands-which bands do you only have white noise?  Perhaps an issue in the changeover mechanism?  I don't have my schematic handy but I believe it uses a 6C4 HFO like many of the Hammarlund receivers and this tube is often a problem so try a substitute for it.

You may need to install a trap at the antenna to reduce the problem of the 6 Mhz. radio station coming in directly via the IF.  I had to do this on the SX-101 I use with my Valiant since on 160 meters there is a broadcast station that rides in directly to the 1650 Khz. first IF in this radio.

[KM1H]

I had to select a 6C4 that worked in mine also, otherwise it had no problems and even the meter works.

I do need the original knob and clutch assembly, it came with a weighted spinner knob!

One of these days Im going to take the time to find a cure for all the 6C4 problems that plague many brands.

Carl

[WQ9E]

Mine came with a nicely installed concentric knob reduction drive which makes CW/SSB tuning very nice.  I decided to leave it as is.

Carl, many of us will be interested in your 6C4 findings; I have several receivers that I have had to use selected 6C4 tubes.