New Project

[K9ACT]

While I was busy gassing with someone at the recent Hamboree, my wife bid on a mystery box and won it for $1.  No one knew what it was so it went begging.  I guess if it doesn't say Johnson or some other boat anchor name, it does not exist.

Turns out it was some kind of Motorola VHF test set for mobile phones.  I have pulled out a gold mine in parts but the real treasure is the Bud cabinet it was in. It is the 9" high one that I have seen receivers of the forties packaged in.  It has a latching, hinged top and is clean as a whistle.

A glance at the attached photo of my 810 RF deck is a clue to my new project.

Looked like a lot of floor space but it quickly became obvious that the 810 will not stand up in the cabinet with the top down.  So I have spent a good deal of time working up a layout that will work.  I built up a chassis from 1/8" sheet and angles and the front panel from the same.

All the parts are mounted now  and I am in the wiring up stage.

The Masonite and wood are quaint and work but I am hoping this will eliminate the RFI problem I have with my SDR.  Keying the transmitter frequently, crashes the receiver.

Next photo will be a little neater looking, I hope.

Jack

[Opcom]

should be interesting to see that. 'lazy' mounting or horizontal?

[k4kyv]

It's OK to lay the 810 down on its side.  Just be sure that the plane of the filament,  grid and plate structure is vertical, so that the filament tends to sag sideways inside the tube.  If you mount it the other way, the sag will tend towards the grid, and eventually result in a grid/filament short.

[K9ACT]

It's OK to lay the 810 down on its side.  Just be sure that the plane of the filament,  grid and plate structure is vertical, so that the filament tends to sag sideways inside the tube.  If you mount it the other way, the sag will tend towards the grid, and eventually result in a grid/filament short.

The tube sheet says pins 1 and 2 must be in a vertical line.  So I mounted the socket that way but forgot to account for the fact that the tube is twisted to lock and the position of the socket does not relate to the actual pins.

The meters ended up on the wrong side of the panel because I milled the holes from the backside instead of the way I laid them out.

Only one "toilet seat" hole and it's all done but does not work.  Look great though.

It won't unload.  Can't get less than about 300 ma at dip.  Same problem on 20 and 80 meters.

With 50 ma grid drive, it shows about 75 ma plate current with no HV on.

It drops to about 50 ma when I remove the connection to the HV supply even though it is off.

Don't know if these are things I only notice because it does not work or if they really are problems.

Any ideas?

js

[K9ACT]

Attached are two pics of the new look.  I was going to shoot them over today but I got it working on 40 and using it is more important than the pics.

The tube socket is mounted on a piece of 4" channel with the fil trans on the opposite side.

The black box is a piece of junk that just happened to be a perfect mounting for the neut condenser which is a screwdriver adjustment on the top.

The grid coil is on pvc that fits nicely around an old 807 base.  I have coils for 160 - 20.  The plate coil is one of a kind from a ham fest.  The others look like big versions of the grid coil but have banana plugs that fit into jacks mounted on the caps with copper brackets made from flattened copper tubing.

Other than that, it's pretty straight forward.

The good news is that it works great on 40 and there seems to be no more barfing up of the SDR receiver.
However, it sure gets hot in there.

Nuff for now.  Gotta go talk to someone on 40.  Called CQ for half an hour before dinner but no joy.

Jack

[K5UJ]

Jack,

That's great work.  The cabinet gives it a Collins look.  What a deal for a buck.  Ur XYL can shop for me at the next flea market.  Wish I could wade in here more but time is taken up with car repair, work, and rebuilding the antenna farm.  I am frustrated by being QRT and having to spend time earning a living instead of futzing around in the yard with rope, galv. steel, wire and insulators.  OTOH antennas are expensive.  I have to be able to pay for all this stuff.  grrrrrr. Maybe I'll check into the Noontime Forum in a few weeks.

73

Rob K5UJ

[K9ACT]

That's great work.  The cabinet gives it a Collins look. 

Turns out, the grid meter is a Collins.  Seems like I never come home from a hamfest without a few meters but finding two suitable ones that match just doesn't seem to happen.

> What a deal for a buck.  Ur XYL can shop for me at the next flea market. 

She also bought a box of nice big variables but not a one I could use.  Seems like everything over 50 pF has been sucked up.

> Maybe I'll check into the Noontime Forum in a few weeks.

Yah.... where ya been?

js

[K5UJ]

Yah.... where ya been?

js

All antennas down.  Rebuilding the whole thing.  Putting up dipoles at 50 feet.