I'm planning to use a bit of silicone and a soldered ground.
John K5MO
I saw that small PC board with individual radial lead capacitor kit available on eBay
but after studying the PC board it appeared that 2 holes needed to be drilled in the
2B chassis. While I'm sure the small PC board cap kit works after installing it on the 2B
chassis, having to drill 2 holes in the chassis to mount the small PC board was not
something I was willing to do. I used the hayseedhamfest Drake 2B capacitor kit that
worked very well and didn't require drilling holes in the chassis.
?
73
Mike W5RKL
?
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I saw that small PC board with individual radial lead capacitor kit available on eBay
but after studying the PC board it appeared that 2 holes needed to be drilled in the
2B chassis. While I'm sure the small PC board cap kit works after installing it on the 2B
chassis, having to drill 2 holes in the chassis to mount the small PC board was not
something I was willing to do. I used the hayseedhamfest Drake 2B capacitor kit that
worked very well and didn't require drilling holes in the chassis.
?
73
Mike W5RKL
?
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Re: Using an R7A with a TR7A
Thanks to all for the documents!
73,
Steve Wedge, W1ES
Time flies like an arrow. Fruit flies like a banana.
On Mon, Jan 20, 2025 at 03:07, Karl du Roi, DK7AL < dk7al@...> wrote: Steve,
have you already seen and checked this piece of information regarding
building an interconnection cable between Drake TR7 and R7:
https://www.dl7maj.de/TR7-R7-cable.pdf
Best regards.
Karl, DK7AL
Am 19.01.25 um 23:13 schrieb Steve Wedge, W1ES/4 via groups.io:
> Folks ¡ª
>
> 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
>
> Time flies like an arrow. Fruit flies like a banana.
>
> Sent from [Proton Mail](https://proton.me/mail/home) for iOS
>
>
>
>
|
On Sun, Jan 19, 2025 at 03:41 PM, Jim Shorney wrote:
>Interesting video but his glitch diode configuration has me puzzled. He complains (rightly so) that the B- was returned to the chassis but connects a reversed diode pair in which one of the diodes returns the B- to the >chassis? The glitch diode implementations I have seen use only a reverse biased diode from B- to chassis ground. Am I missing something?
With the 2nd diode installed (rvs connected pair).....the pair? ensures the B-? ?can't wander more than? +/-? .7 vdc? ?from chassis potential.? ?In the old days, something like a 10 ohm resistor from B- to chassis? would accomplish the same thing.? The concept in both cases was to float the B- from chassis potential just enough..... to be able to measure plate and grid current.? The issue with the 10 ohm resistor is if the anode arcs to the grid, or chassis, the fault current path is up from the chassis, through the resistor.... and back to the B- of the filter caps..... completing the loop.....and of course the resistor grenades.? With any anode to grid arc, or B+ to chassis arc, only one diode is required ( UN-banded end? facing the chassis).? ?I install the 2nd diode just to ensure the B-? can never wander more than +/- .7 vdc from the chassis. With any GG amp that has a grid over current circuit in it, it will not function correctly, since the 2nd diode is electrically in parallel with the? typ small value resistor used in the grid over current assy.... ( typ wired in series with the negative end of grid meter / grid shunt..... and chassis).? ?The V drop across the low value resistor is now in parallel with the 2nd diode, biasing the 2nd diode on.? Then grid current flows? up from the chassis....and through the 2nd diode........ instead of up through from the chassis.... and through the small value grid sense resistor...... which results in low or no? grid current readings, even though plate current reads normal, and PO is normal.?? That's why only one diode is used on ameritron amps that have the grid over current scheme installed.? ?In older books, you will see the rvs connected pair of diodes across? both the grid and plate current meter..... and that scheme still works......? ?with or without the grid overcurrent sense circuit installed.? In the L4B in question, the customer paid for packing and shipping to Ron, plus a helluva lot of money up front, only to be told it was unrepairable...and Ron wanted to keep the amp? and the HV supply....and the money.? Customer was told when the plate xfmr heats up, it shorts out.? Nothing wrong with the plate xfmr.? It's all fixed now.....plus the customer got his money back from Ron.? ? Dunno, but Ron might be starting to lose it.? ?And that could result in a dangerous scenario, esp with +2650vdc? involved.?
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Re: Using an R7A with a TR7A
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:
toggle quoted message
Show quoted text
Folks ¡ª
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
Time flies like an arrow. Fruit flies like a banana.
Sent from [Proton Mail]() for iOS
|
Re: Using an R7A with a TR7A
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 ¡ª
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
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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
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Re: PS7 Fault, Troubleshooting & Repair
Thank you, Jim. This weekend while using the TR7/PS7 in the NA QSO Party, the PS7 tripped out a couple of times. I went back in this evening and recalibrated the overcurrent setting based on your referenced article. It now trips out right at 30 amps.?
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Re: Using an R7A with a TR7A
Steve, ? The attached is the cable that you can build.? It is what I am using for my R7 / TR7 transceive? ? 73 Dale AF7WH ?
toggle quoted message
Show quoted text
From: [email protected] <[email protected]> On Behalf Of Steve Wedge, W1ES/4 via groups.io
Sent: Sunday, January 19, 2025 2:13 PM
To: [email protected]
Subject: [DRAKE-RADIO] Using an R7A with a TR7A? 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.? Time flies like an arrow. Fruit flies like a banana.
|
Folks ¡ª
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
Time flies like an arrow. Fruit flies like a banana.
|
Re: Replacement Male connector for 2BQ?
I meant replace with DIN connector. That looks pretty old-school with a metal plug.?
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I've got a 2B to recap, and I agree....? with the Qmultiplier? it's a fantastic vintage CW rig.? I pair mine with the flavor of the day CW rig and it's perfect for that.
I found those capacitor boards on ebay from the seller Affinity for Artifacts for about $3 ea, or with caps for 9-10$.? Makes for a nice replacement at a modest price.
There's a variety of shapes and sizes, but here's a sample
?
?
John K5MO
?
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TR-4C excess drive on 20m
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.
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Drake 5 pin accessory connector
I'm talking with a guy that is having samples made of this connector even as we speak/type.
When this comes to pass I'll post the info, but it looks quite promising.
?
John K5MO
|
My favorite receiver.
?
Happy to hear you "rectified" the hum problem!
?
Here is another option:
?
https://www.ebay.com/itm/126675460504?
?
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Thank you Jim and Jim for all the information. Yes I certainly hope all is OK with Ron.
Tim
WB8UHZ
On Sunday, January 19, 2025 at 09:41:20 AM EST, Jim Shorney via groups.io <jimnu0c@...> wrote:
Interesting video but his glitch diode configuration has me puzzled. He complains (rightly so) that the B- was returned to the chassis but connects a reversed diode pair in which one of the diodes returns the B- to the chassis? The glitch diode implementations I have seen use only a reverse biased diode from B- to chassis ground. Am I missing something? /g/DRAKE-RADIO/files/Glitch%20protection%20D_a_02.pdfAt any rate, it does look bad for Ron. The eHam reviews after 2022 are brutal. I hope he is doing OK.
On Sat, 18 Jan 2025 22:52:15 -0800
"Jim VE7RF via groups.io" <jim.thom@...> wrote:
> Scott Mitchell? (KB!SEL)? owns? amprepairguy.com? ?and also Harbach Electronics.
>
> Here is the L4B in question.
--
73
-Jim
NU0C
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Re: Replacement Male connector for 2BQ?
Since the female jack is just held in place with screws maybe I will just put in molex male/female. The radio is for me anyway. Any other ¡°old looking¡± jacks/plugs that would work in that space?
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Re: Replacement Male connector for 2BQ?
For the record, all I have is the connector itself and no backshell.? Thes are still available but I've forgotten where I bought mine (new) a few years ago.
Steve Wedge, W1ES
Time flies like an arrow.? Fruit flies like a banana.
Sent with secure email.
On Sunday, January 19th, 2025 at 11:31 AM, 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?
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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
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Re: Replacement Male connector for 2BQ?
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
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Karl du Roi, DK7AL
Jim Shorney
Robin K4IDC
Dale Dean - AF7WH
Marcus PY2PLL
