HEATH APACHE/SB-10 SSB PTT MODS?

[K7NCR]

Greetings from NW Montana! Is it really as easy to do PTT on the apache as just relay contacts paraleling the plate switch? Any other curcuits need switched? Also, I'm getting a SB-10 SSB adapter, and it has VOX or MANUAL xmit, would consider doing PTT on it as well. Any thoughts? I'm just getting started on my road to "buzzard-dom", but enjoy BA gear op much more than any rice-box!
Norm Palin K7NCR

[WU2D]

Norm,

God's summer home is in Montana - Big Sky!

You aren't one of those Kalispell hippies are you?

I spent a year in Bozeman when I was first married and we brought the kids back to show them MT. That was the best year of my life and I am glad to say that it is still a great place.

I am in a similar predicament on my Apache and will be doing a PTT mod this fall.

Mike WU2D

[K7NCR]

Hi!
No, not a Kalispell Hippie, but a good ol' boy kalispell native, logger-hugger, deer shooter, nuke em' till they glow and shoot em' in the dark kinda guy! I think the PTT for both may not turn out to be that complex.
Norm K7NCR

[WU2D]

Great Norm,

Don't mind the Kalispell crack- I was just fishing with an attactor pattern and hoping for big trout to rise - Hi.

I solid stated the Apache so I had room for a 24VDC DPDT octal relay. No idea how I will hook it up yet but it is sitting in there. I guess the first idea is to make 24 VDC! I also need to install a Heath connector which gives me the standard "Heath" PTT hookup. Actually I have a PL-68 style connector which will mount with no chassis drilling.

Mike WU2D

[WU2D]

OK Norm,

The Apache is officially back on the bench. As you remember, I was just getting ready to do a PTT relay when I shut the project down for the Summer - time flies...

First I wanted to undo some things that did not make sense to the group. I had put in a fancy time delay circuit that delayed the center tap on the HV until the fills lit up. This was ripped out and I put in a 5 Amp MOV on the primary side.

I replaced the old Heath cord and put in a 3 wire cord. That was a good idea but when I added a rear panel fuse, I was not careful and got it too close to the cutout relief on the case. I had to drill another hole and move the fuse - God that hurts. I plugged the original hole with a grommet.

I have mounted a jack on the front - now we go back to your question - what do we want to switch in the indian and what do we want to do about antenna switching and muting the RX?

Mike WU2D

[K7NCR]

Hi!
The mute connections on the back and the accessory jack conn. for the TR relay work fine for me in AM, but when used with the SB-10 require some too complex seeming setup. My rig still has the tube rectifiers, was thinking of building something outboard, that would plug into accessory jack. I'm sure between us and this crew we can figger it out!

[WU2D]

Great norm, but did you go with a relay, how did you make power for it and what did you key inside the rig?

Mike WU2D

[John K5PRO]

You really want to agonize those appliance ops using that SB10. The carrier will drift in and out as it warms up, so keep that in mind, when you hear them complaining about the carrier in the background. Kind of Hybrid AM...
73
John

[K7NCR]

My SB-10 has about as much suppresion as my Swan Cygnet,, rice-box tuners can just deal with it!
I am still just planning my PTT. Was considering a 6 volt relay powered from fil. voltage. I think there are enough spare pins on the acc. socket for that. If I switch the same circuits as the t-r switch on the front panel, it will also switch the normal mute terminals. I could even parallel the vox relay on the SB-10 so it has PTT, and keys the Apache AND the SB-10, instead of leaving it in TX and just using the VOX/SB-10 when in SSB.
I've been so wrapped up in the Mohawk rest that I have not had much time for other ideas. I've just been throwing the TX switch on the few times I've been on so far.
I'm finaly done with the alignment, and may try some contacts with it this weekend. I'm still waiting on my LSB crystal, though, so I won't button it up just yet.
Norm K7NCR

[WU2D]

I have a few ideas on how I will do it.

I have one of those common 24VDC octal relays with two DPDT contacts. My idea is to use a small 24V CT transformer with a bridge. The relay will work on the 24VDC (unfiltered) and the the CT will get a large cap and a 6VDC regulator. This regulated 6V will light up the low level tubes in my modulator to reduce hum.

I will simply put the NO contacts across the two contacts of the plate (TX) switch.

The relay will be keyed off the mic jack to ground.

Mike WU2D

[WU2D]

OK I got the PTT installed in the Apache and it works FB. The idea is simply to parallel the relay across the two poles of the PLATE switch which is labelled STANDBY-TRANSMIT on the front panel.

This is a very simple circuit but figuring how to run the five #22 wires to the front panel turned out to be not so simple. There was no more room to put wires through the existing grommets so I had to install a couple of grommets in the partition panels.

The circuit basically lives on a single terminal strip right next to the new relay socket (which originally was one of the 5R4 sockets). A new 24VAC transformer is added to the side wall. Everything fits under the transformer - barely. 

Good Luck!

Mike WU2D

[N3DRB The Derb]

I ran a sb10/apache combo along with a mohawk at one time. I cant tell you how many "OUTSTANDING" audio reports I got, not on am, but on slopbucket! compared with filter rigs, the audio on the sb10 is pretty broad. I had em on right before I had my first collins 32v2 75 A2 combo in 1984 or 5 or 6 something, right after I got my General.

The Collins twins were 100 bucks total, and the heath stuff was take it away, but you have to take all of it deal. Frankly, I thought the 32V2 sucked. It was constantly breaking down, and always little hard to get to things way underneath something else. I operated the Heath stuff for almost a full year - a record in those days when my rig turnover was very high - never a problem.

[WA2ONK]

I added PTT using a 12vdc dpdt octal base relay in one of the unused 5R4 sockets after I solid stated the HV supply. I replaced the filter caps, the new ones are a lot shorter than the originals. That allowed enough room to mount a wal-wart dc xformer using existing holes in the chassis on a fabricated bracket. Made the necessary connections at the accessory socket, works great, a real worth while mod.

Chuck..