Steve,

have you already seen and checked this piece of information regarding building an interconnection cable between Drake TR7 and R7:



Best regards.

Karl, DK7AL

Am 19.01.25 um 23:13 schrieb Steve Wedge, W1ES/4 via groups.io:

Yes, if you are willing to build you own. An example of the control cable has already been posted to this thread. FWIW I used low capacitance coax for the PTO and 40MHz reference signals but RG-174 or even RG-58 should be OK.

For the RX antenna path you need a pair of cables with RCA connectors on each end. Good quality RG-58A/U is fine. There is a jumper inside the TR7 that needs to be cut to pass the RX antenna path through the R7. The beauty of this system is you can either use the TX antenna for RX on both rigs or switch a separate RX antenna to either rig. This is also a handy place to insert things like an RX preamp or a noise phaser.

Speaker audio can optionally be passed from the TR7 through the R7 via a 1/4 inch to RCA plug cable.

On Sun, 19 Jan 2025 22:13:15 +0000
"Steve Wedge, W1ES/4 via groups.io" <w1es@...> wrote:

Folks —

I have someone asking me to get their R7 to work with a TR7. I just want to make sure that the connectors and cables are still obtainable.

Any insights into this?

Steve Wedge, W1ES

--

73

-Jim
NU0C

I think someone was having problems with two of the 10M bands with a 4-line rig recently. I happened to see these and thought I'd pass the ad along:



Thanks,
Barry - N4BUQ

开云体育

开云体育

Gentleman;

Recently I acquired a TR-4C / VF-4C in good shape for my needs. Realigned it following the manual and after that I got the following CW power at 115Vac mains:

10m = 135W = 450mA
15m = 150W = 440mA
20m = 175W = 460mA
40m = 205W = 430mA
80m = 210W = 450mA

After tuning I usually set the XMTR GAIN / X-CW up to the point where power / plate current does not rise anymore.

For every band this point falls from 9 to 10 o'clock, except 20m where this point occur around 1 or 2 o'clock.

I always use between every mic / radio a small audio compressor / limiter based on the MAX9814 chip. Two objectives: keep audio level constant of course and avoid mic inputs overload. Good results on different combinations of radio / mics (JBL headset / IC 735, Elecraft K3S or Elecraft MH2 hand mic X TR-4C).

I noticed that on 20m seems that there's excess of drive on TR-4C. I understood that TX AGC is not a "real ALC" but sort of clamper (?), despite of the behavior I measured (e.g. variable negative voltage feed back to TX IF Amp G1, keeping the SSB envelope in a good shape). But looks like it's not behaving as it should on 20m only. I measured the same variable negative voltage at IF Amp G1, basically the same as any other band.

Attached there's a picture of a waveform monitor, long letter "O". I'm aware that 20 and 80m does not use the xtal oscillator so VFO connect direct to TX mixer and may be an higher level of injection can be the responsible.

But 80m behaves equally to any other band up to 10m, the exception is 20m.

The average power is easily detected at any analog wattmeter I have, during normal speech any band ranges from 25-35W but 20m varies from 70 to 80W.

Any clues why 20m "chain" is behaving like this?

73, Marcus PY2PLL.

I am looking for a replacement Blower Wheel for an L4B amplifier.? You can reply here or to my email address on QRZ.

73, Ron

ND4R

AFAIK 5AB2 is the designation of the 4 pin version. The added center pin for the 5 pin version may have been unique to the car stereo universe and I have never seen a separate number for that one or for a backside cap although I have seen rubber caps on autosound speaker harnesses. Maybe someone has an old Cinch catalog from that era. There is a 10-lot of the are plug assembly up on eBay right now. He calls it a battery plug.

On Sun, 19 Jan 2025 08:31:37 -0800
"k3stx via groups.io" <k3stx@...> wrote:

Thanks for the info on the Cinch connector. ?My “plug” that holds the pins in place lost its little clamp ears; I need the whole plug ( it just solder pin assembly. Any idea of the name of the connector that holds the 4 pin plug?

--

73

-Jim
NU0C

On 2025-01-18 19:20, Gary Follett via groups.io wrote:

knew a LOT about what Zenith products should look like and would not

them pass tests) we would have been shown the door, that same day - no
two weeks notice!

*** "The Quality goes In before the Name goes On".

- Jerry, KF6VB

The Drake builds that I have seen have been very good. But having been both a line tech and a customer service tech at electronics manufacturers I can say that assemblers do have bad days, they often chit-chat amongst themselves too much, and mistakes happen. We were all under pressure to get stuff out the door and things get missed in hurried visual inspections. If it works to spec it hits the road. I once knew a fellow who did a full alignment on any new radio be bought because he knew they were often aligned to meet spec, not necessarily for best performance. I have also seen line "techs" who had no idea what they were doing. They were just following work instructions and if they ran into an unusual problem they did not have the skills to troubleshoot and repair it. Quality suffered.

On Sat, 18 Jan 2025 17:47:04 -0800
"Dave W7GZ via groups.io" <w7gz@...> wrote:

I got in a Drake R-4B (S/N 89xx) for repair this week that I consider to have quite poor build quality. I guess the assembler was having a bad day when he built this one.

--

73

-Jim
NU0C