The Transmit 2 is the ultimate version of the Broadcast, combining features from the 24V Dual and the AP, with additional features and options.
Transistors:
The original Broadcast has featured several different germanium transistors over the years, and many others have been used in reproductions. The germanium transistor I use may vary batch to batch, but I have used all of the following in this circuit and all work very well: OC71, TG5S, 2N527, 2N404A, AC128, AC162.
The silicon transistor may vary as well. I started with the 2N4033, rumored to be used in the Broadcast AP, but it doesn’t like the higher voltages. I have also used a 2n4037, which can handle the 18V, but not the 27V. Recently I have used the 2N327A/B, which is lower gain, but can handle the higher voltages.
The first stage transistor is an NOS BC549C.
Voltage:
Should only be used with a 9V center negative DC power supply. It has an internal charge pump to boost the voltage internally for the selectable 18V and 27V. Select higher voltages for more headroom and output.
Tone:
The low cut control is a staple of the Broadcast, but the Transmit 2 also includes the most requested feature for the circuit: a high cut control. Especially useful at high volume for cutting down the peaks to optimum levels.
Also included are selectable ranges for the cuts, normal and maximum.
Output transformer:
I decided to use the Hammond 142A in the Transmit 2. It features the same specs as the Triad and OEP transformers used before, but to my ears it seem to hold the low end a bit better.
Trim Pots:
There are two internal trimpots to adjust the gain range of each channel. I set the low (left side trimmer) to slightly less than the middle and the high slightly above. These can be adjusted to suit your taste.
All other components used are premium, including Lumberg DC jack, Alpha pots, 105C electrolytics, 1/2W carbon film resistors, and SBP enclosures.
Color:
Get notified by email when this product is in stock.
The Transmit 2 is the ultimate version of the Broadcast, combining features from the 24V Dual and the AP, with additional features and options.
Transistors:
The original Broadcast has featured several different germanium transistors over the years, and many others have been used in reproductions. The germanium transistor I use may vary batch to batch, but I have used all of the following in this circuit and all work very well: OC71, TG5S, 2N527, 2N404A, AC128, AC162.
The silicon transistor may vary as well. I started with the 2N4033, rumored to be used in the Broadcast AP, but it doesn’t like the higher voltages. I have also used a 2n4037, which can handle the 18V, but not the 27V. Recently I have used the 2N327A/B, which is lower gain, but can handle the higher voltages.
The first stage transistor is an NOS BC549C.
Voltage:
Should only be used with a 9V center negative DC power supply. It has an internal charge pump to boost the voltage internally for the selectable 18V and 27V. Select higher voltages for more headroom and output.
Tone:
The low cut control is a staple of the Broadcast, but the Transmit 2 also includes the most requested feature for the circuit: a high cut control. Especially useful at high volume for cutting down the peaks to optimum levels.
Also included are selectable ranges for the cuts, normal and maximum.
Output transformer:
I decided to use the Hammond 142A in the Transmit 2. It features the same specs as the Triad and OEP transformers used before, but to my ears it seem to hold the low end a bit better.
Trim Pots:
There are two internal trimpots to adjust the gain range of each channel. I set the low (left side trimmer) to slightly less than the middle and the high slightly above. These can be adjusted to suit your taste.
All other components used are premium, including Lumberg DC jack, Alpha pots, 105C electrolytics, 1/2W carbon film resistors, and SBP enclosures.
Image 1 of 25
Image 2 of 25
Image 3 of 25
Image 4 of 25
Image 5 of 25
Image 6 of 25
Image 7 of 25
Image 8 of 25
Image 9 of 25
Image 10 of 25
Image 11 of 25
Image 12 of 25
Image 13 of 25
Image 14 of 25
Image 15 of 25
Image 16 of 25
Image 17 of 25
Image 18 of 25
Image 19 of 25
Image 20 of 25
Image 21 of 25
Image 22 of 25
Image 23 of 25
Image 24 of 25
Image 25 of 25