Browning R-2700A and S-Nine (23)

[theradiotech]

Anyone know where to find some info on these? Manuals, schematics ect. Had one brought in today missing the control cable. So need to make a new one. Then check unit to see what other problems it may have.

[238]

Maycomm has a CD with all the Brownings on it. 238

[theradiotech]

Thanks 238. I went and found that. Time to order!

I made a control cable. That was easy to figure out. Changed out the old 2 pin mic jack to a 4 pin. It was cracked anyway. Repalced a resistor in the transmitter and got it working great.

Now for the receiver.

[ak3383]

I have a set of Brownings that my Dad bought new, they are the 23/S9 and R-2700A. I know that Browning had 2 models of the 23/S9 transmitters with the only difference being the channel selector knob. One version (the one I have) has a small channel selcetor knob and a small ring of channel numbers 1-23. The other 23/S9 tansmitter had a channel selector that was much bigger and shaped like an arrow with the channel numbers painted on the face. I wanted to know if anyone knew which of the two models was the very first 23/S9 model to come out?

[238]

I believe the one you have is 1'st one. 238

[2600]

I'm not sure of the model years, but the R2700 originally came with a 6-channel transmitter called the "T2700". Never have seen one, except in a picture. Maybe 1960 or 1961. Not sure. Could be that this receiver was also sold with the later "S9" transmitter. Before my time.

A year or two later the R2700A was offered with the "S9" transmitter. Had 9 channels.
A popular upgrade was the "23S9". The same transmitter, but with a 23-channel selector and all the crystals. Early ones had a metal plate under the knob with the channel numbers screen-printed on them.

Next year (maybe), the R27 receiver was offered with the "S23" transmitter. There was more than one version of this, but the info is skimpy. Some of them had a 6BQ5 modulator, others had a smaller 6AQ5.

Next came the "Golden Eagle". Didn't say "Mark one" anywhere on it. Seems to me this would be 1968. Came with a transmitter that had the face plate redesigned, a 4-pole relay that would light an "On The Air" light in the receiver. This receiver used a Collins mechanical filter for the 455 kHz IF. Some folks say that this receiver has a unique sound, and better rejection. First model of the AM transmitter to have the tune and load on the rear panel, rather than on the side like the previous models. No sideband yet.

1969 brought the Golden Eagle Mark II. The receiver has SSB capability. Sorta. No expensive mechanical filter in the receiver. Transmitter has the parts arranged a bit differently than the previous year's model. The 1969 product line included a separate SSB-only transmitter called the SSB-15. They sold a combiner box that would connect to the receiver, and had a switch to select the transmitter. A complete Mark II station, including the "Business license only" base linear was five cabinets wide. Took a big desk for that station.

The Mark III was the 1970 model. Stayed in production for around 6 years. Trouble with getting the prototype 23-channel Mark IV to work (at all) is probably the reason it was sold for so long. Early Mark III radios are different from the late version. Not sure what year that change was made. Maybe 1973. The Mark III could be ordered with the SSB/AM transmitter in a cabinet the same size as the receiver. The "low-cost" option was a 23-channel AM-only transmitter that was identical to the late Mark II transmitter, but with a new paint job to match the Mark III receiver. That's the transmitter in my siggy below.

I have completely left out the "Business" versions sold over the 60s and 70s. Don't know how many of those were sold, but they turn up now and again.


73

[ak3383]

Thats a very cool looking channel display, it goes well with the transmitter. Looks like Browning made quite a few radios in their day. I always wondered how the Mark III's or IV's did on sideband, it seems like it would be pretty tricky to use those radios on sideband with the tubes and all.

[2600]

Well, the subject of sideband on a Browning will prompt a wide range of opinions.

My take is that the transmitter is not too bad, and the receiver sucks.

On sideband.

Drifts too much.

No, it's not the dial drift that's the problem. The dial on the receiver is very stable so long as it's maintained properly and hasn't been exposed to too much moisture over the years.

The drift problem that ruins SSB receive takes place in the CARRIER oscillator. This is what makes a SSB receiver different from AM. You have to 'put back' the carrier that was removed in the SSB transmitter at the other end.

Every other SSB CB radio but Browning uses a crystal for this internal-carrier frequency. Browning uses a low-precision coil and capacitors to build this oscillator circuit. Not a crystal.

And it drifts. A LOT more than the dial drifts. Just makes it too squirrelly for my tastes.

But like I said, opinions will vary.

73

[Sandbagger]

Aug 6, 2009 0:44:12 GMT -5 2600 said:

Well, the subject of sideband on a Browning will prompt a wide range of opinions.

My take is that the transmitter is not too bad, and the receiver sucks.

On sideband.

Drifts too much.

No, it's not the dial drift that's the problem. The dial on the receiver is very stable so long as it's maintained properly and hasn't been exposed to too much moisture over the years.

The drift problem that ruins SSB receive takes place in the CARRIER oscillator. This is what makes a SSB receiver different from AM. You have to 'put back' the carrier that was removed in the SSB transmitter at the other end.

Every other SSB CB radio but Browning uses a crystal for this internal-carrier frequency. Browning uses a low-precision coil and capacitors to build this oscillator circuit. Not a crystal.

And it drifts. A LOT more than the dial drifts. Just makes it too squirrelly for my tastes.

But like I said, opinions will vary.

73

I couldn't agree more. I was trying to listen to SSB on my Mk III and the drifting of the BFO is clearly evident. I wondered if it was something unique to my radio, but evidently it's par for the course. And because it does not use a crystal filter in the IF, the bandwidth is a little wide and you can tune in either sideband on either mode and the noise floor will be a little higher.

If you're a serious SSB'er, a Browning is probably not your best choice in radio.

[Tombstone (R.I.P.)]

My Mark III is a chore to work ssb with and with the Siltronix 90 slider on the transmitter it's even worse. Once the slider stabilizes it's not bad but between the receiver and transmitter it's a bear. I get good reports with it though. I find it a lot easier to use my Cobra 2000 for sideband.

Tombstone

[vanlifeson]

Jun 6, 2009 14:01:30 GMT -5 2600 said:

I'm not sure of the model years, but the R2700 originally came with a 6-channel transmitter called the "T2700". Never have seen one, except in a picture. Maybe 1960 or 1961. Not sure. Could be that this receiver was also sold with the later "S9" transmitter. Before my time.

A year or two later the R2700A was offered with the "S9" transmitter. Had 9 channels.
A popular upgrade was the "23S9". The same transmitter, but with a 23-channel selector and all the crystals. Early ones had a metal plate under the knob with the channel numbers screen-printed on them.

Next year (maybe), the R27 receiver was offered with the "S23" transmitter. There was more than one version of this, but the info is skimpy. Some of them had a 6BQ5 modulator, others had a smaller 6AQ5.

Next came the "Golden Eagle". Didn't say "Mark one" anywhere on it. Seems to me this would be 1968. Came with a transmitter that had the face plate redesigned, a 4-pole relay that would light an "On The Air" light in the receiver. This receiver used a Collins mechanical filter for the 455 kHz IF. Some folks say that this receiver has a unique sound, and better rejection. First model of the AM transmitter to have the tune and load on the rear panel, rather than on the side like the previous models. No sideband yet.

1969 brought the Golden Eagle Mark II. The receiver has SSB capability. Sorta. No expensive mechanical filter in the receiver. Transmitter has the parts arranged a bit differently than the previous year's model. The 1969 product line included a separate SSB-only transmitter called the SSB-15. They sold a combiner box that would connect to the receiver, and had a switch to select the transmitter. A complete Mark II station, including the "Business license only" base linear was five cabinets wide. Took a big desk for that station.

The Mark III was the 1970 model. Stayed in production for around 6 years. Trouble with getting the prototype 23-channel Mark IV to work (at all) is probably the reason it was sold for so long. Early Mark III radios are different from the late version. Not sure what year that change was made. Maybe 1973. The Mark III could be ordered with the SSB/AM transmitter in a cabinet the same size as the receiver. The "low-cost" option was a 23-channel AM-only transmitter that was identical to the late Mark II transmitter, but with a new paint job to match the Mark III receiver. That's the transmitter in my siggy below.

I have completely left out the "Business" versions sold over the 60s and 70s. Don't know how many of those were sold, but they turn up now and again.


73

[

I have a MK 2 receiver with the Collins mechanical filter. Is this an early version? Because I see some Mark two receivers without the Collins . Thank you

[2600]

Seems to me the price of the Collins filter went way up, and Browning dropped it from later production runs of the Mark 2.

Or so I was told.

73

[cbrown]

Feb 8, 2022 1:24:43 GMT -5 2600 said:

Seems to me the price of the Collins filter went way up, and Browning dropped it from later production runs of the Mark 2.

That is the way I heard it, too.

[vanlifeson]

So would a Mark 2 receiver with the Collins filter be rare?

[2600]

Yes.

73