RCA Senior Voltohmyst

The RCA WV-98C Senior Voltohmyst (SN 201001 1104)I picked up at the hamfest yesterday looks to be in pretty good working order.

RCA WV-98C Senior VoltOhmyst
RCA WV-98C Senior VoltOhmyst

No smoke, popping or other unusual sounds/odours when I plugged it in. Some initial testing with batteries and some resistors suggests a bit of recalibration or maybe a bit of repair might be needed though.

Fortunately I was able to find a manual for it at the Boat Anchor Manual Archive.

Removing four screws from the back lets you take the back cover off (a fairly substantial chunk of cast aluminum) revealing the innards of the meter.

Back of the RCA Voltohmyst
Back of the RCA Voltohmyst
Voltohmyst circuit board
Voltohmyst circuit board

The blue adjustment screws are trim pots used for adjusting the meter calibration.

One thing that surprised me was the presence of a soldered in D cell.

Top part of the Voltohmyst. Badly corroded 1.5V D cell and transformer
Top part of the Voltohmyst. Badly corroded 1.5V D cell and transformer
1.5V Battery
1.5V Battery

No idea what vintage the battery is or what it’s used for (at the moment), but my multi-meter showed it still had 1.4 V across it. The battery has definitely seen better days. I think I’ll see about replacing the battery with a battery holder so it can be removed and replaced in the future. Fortunately it looks like the wires have enough slack to work with.

The rest of the meter looks to be in pretty decent shape, and pretty clean. Without taking off the face of the meter, it’s a little hard to get in there to check out the middle. There are two tubes in the unit, a 12AU7 and 6AL5.

Lots of colourful wires at the range selector and mode selector switches.

Range selector switch
Range selector switch
Mode selector switch
Mode selector switch

The probe for the meter is a big chunky thing, about the size of a Sharpie marker.

Voltohmyst probe
Voltohmyst probe

Next step will be to go through the manual and read a bit more about the meter works before I try to dive in  and replace things.

Charleston Hamfest 2018

This year’s hamfest was a busy one for me and a far cry from last year’s hamfest where I could only stay a short while.

The day before the hamfest was a full day of helping set up tables and chairs for the hamfest, and then helping some of  the vendors that showed up early to unload and set up. Hamfest day started at 6AM helping more vendors unload and set up followed by the doors opening at 8AM.

One of the nice things about being around to help with the set up is that as the vendors are unpacking, you get to see what everybody has and, if you find something you really want, buy it before the crowd gets there.

I gave my two short forum presentations to an audience of maybe 6 or 7 people I think. Got some decent interaction out of them, so I was pleased with how they went.

Found a few things to pick up at this year’s hamfest, and a bunch of other things that were in the “ooo, I want” category.

Someone left a stack of old QST magazines from 1951 and Popular Electronics from 1962 (a year before ZIP codes were introduced).

1951 QST
1951 QST
1962 Popular Electronics
1962 Popular Electronics

I’m going to enjoy reading through these. The ads in these old magazines are almost as fun to look through as the actual content.

There was only one person tailgating this year, but he had a neat looking RCA VOM that I thought would be neat to have in the toolkit. He also threw in this odd HP probe with an N connector, so I also picked up an N/SO239 adapter from another vendor to go along with it.

RCA WV-98C Senior VoltOhmyst
RCA WV-98C Senior VoltOhmyst
HP Probe
HP Probe

Hamtubes.com was a new vendor at the hamfest this year (making a stop here on their way to Hamcation next weekend) and they had a pretty large selection of tubes. Found all the tubes I need for the Hammarlund, although I failed to notice on my list that I needed two 6BA6 tubes instead of just one.

Tubes for the Hammarlund restoration project
Tubes for the Hammarlund restoration project

Most of the tube replacement kits I’ve seen on eBay were in the $65 range, so at $33 for these ($36 if I had gotten that other 6BA6 I needed), I’m pretty pleased.

A copy of VHF/UHF Manual (4th ed) from the RSGB, some Anderson Powerpoles to replenish my stock, and a blister pack of SuperGlue rounded out my hamfest purchases for this year.

VHF/UHF Manual
VHF/UHF Manual

The afternoon VE testing session had a pretty decent sized crowd of 17 testers. I think 14 of the 17 left the session with either a new license or an upgrade.

It was a pretty good hamfest this year. Lots of full tables and lots of vendors. Heard attendance through the door was down a little bit though, but the crowds didn’t seem too much smaller to me. I had a good time this year. Looking forward to the next one.

A couple of hamfest forum presentations

I’ve been roped into filling in one of the time slots for the forum presentations at the Charleston Hamfest coming up in a couple weeks.

Rather than doing one long presentation, I decided to do two shorter presentations. One of them will be pretty easy to do, the other one I’ll have to research and make up as I go along.

This will be the first time I’ve done a hamfest forum presentation, but not the first talk I’ve done. It’s been a while though.

Also on the list for presentations at the hamfest are ARRL SC Section Manager Mark Tarplee, N4UFP, ARRL Roanoake Division Director Dr. Jim Boehner, N2ZZ, and ARRL CEO Tom Gallagher, NY2RF.

WA4USN QSL cards

One of the club‘s older members was clearing out some old stuff and offered up a stack of WA4USN QSL cards to anybody who wanted them, so I grabbed a couple of them.

Years ago he had been given a stack of postcards and information cards by the USS Yorktown Association, so he turned them into QSL cards.

One card features a drawing of the USS Yorktown from before it was modified to enclose the bow portion of the ship. The reverse side lists some interesting statistics about the Yorktown during WW II.

The other card (formerly a USS Yorktown Association “Pay your dues” reminder postcard) has a Grumman F6F-3 Hellcat on the flight deck of the Yorktown, in front of the island.

While they aren’t old cards, I think they are a nice use of some cards that probably would have ended up in the dumpster.

Battery box idea

I’ve got four SLA batteries that came out of my APC UPSs when I replaced the batteries with fresh ones. There were five, but one of the batteries turned out to be dead dead.

They work quite nicely as power supplies for the radio, and I’ve made up wiring harnesses that let me use one or two of them to run the radio on. They work pretty well and give me a couple hours of radio time at full power output (100W) at around a 20-25% duty cycle.

We’ve got some nesting wooden boxes that look kind of like pirate treasure boxes that aren’t doing anything at the moment except taking up space. They used to belong to Connie’s mother, probably a good find at a yard sale. I thought they’d come in handy for some project eventually.

Small pirate treasure box
Small pirate treasure box

Then I think to myself: “Self, how about putting the batteries in them?”

“Capital idea old chap. Let’s try it out”

As it turns out, the smallest box is just big enough to hold all four of them.

Batteries in the small box
Batteries in the small box

Five batteries will fit in the medium sized box with a little bit of room around them.

Batteries in the medium box
Batteries in the medium box

The medium sized box gives enough head room to make some holes to run wiring and Powerpole connectors through the side of the box, and maybe some digital voltage/current meters. It’s pretty hefty though, coming in at 13.2 kg (29 lbs). A fifth battery in the box would add another 2.5 kg to that. A fair bit to lug around, but this would be intended for setting up portable but not mobile operations somewhere like the back yard, or a field somewhere.

This should be a good weekend project to work on one of these days.